


G vvdUruiA- <x, ^OO^fxJvJCLccJ^/ikioJjLcl^ 



£xxjllsJlA> 



111-] 




Book , (°,4SSk 



UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 380 

Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



January 15, 1917 



ENDOTHIA PARASITICA AND 
RELATED SPECIES 

By 

C. L. SHEAR, Pathologist, and NEIL E. STEVENS, Pathol 

ogist, Fruit-Disease Investigations, and RUBY J. TILLER, 

Scientific Assistant, Office of Investigations 

in Forest Pathology 



CONTENTS 



Page 

Taxonomy 1 

Introduction 1 

The Genus Endothia 3 

The Species of Endothia 13 

Morphology and Development .... 22 

Mycelium 22 

Stromata • . . . . 23 

Spore Measurements 30 

Physiology 36 

Cultural Studies 36 

Distribution of the Species of En- 
dothia 4g 



Page 
Physiology— Continued 

Discovery of Endothia parasitica In 

China . ^ 54 

Discovery of^Endothia parasitica in 

Japan 58 

Present Distribution of Endothia 

parasitica in America 59 

Host Relations of the Species of En- 
dothia 59 

Summary 74 

Literature Cited 77 




WASHINGTON 
GOVERNMENT PRINTING OFFICE 

1917 



" 



' 



BUREAU OF PLANT INDUSTRY. 

Chief of Bureau, William A. Tailor. 



Office of Investigations in Forest Pathology. 

scientific staff. 

Haven Metcalf, Pathologist in Charge. 

George G. Hedgcock, Emile P. Meineeke, and Perley Spaulding, Pathologists. 

J. Franklin Collins, Carl Hartley, William H. Long, and James R. Weir, Forest Patholo- 
gists. 

Samuel B. Detwiler, Forest Inspector. 

G. Flippo Gravatt, C. J. Humphrey, and N. Rex Hunt, Assistant Pathologists. 

Roy G. Pierce, Forest Assistant. 

John S. Boyce, Ruth M. Fleming, Ernest E. Hubert, Gilbert B. Posey, Paul V. Siggers, 
and Ruby J. Tiller, Scientific Assistants. 



P. of D. 
MN 25 1917 



UNITED STATES DEPARTMENT OF AGRICULTURE 




J&f'^i. 



| BULLETIN No. 380 



Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 




January 15, 1917 



ENDOTHIA PARASITICA AND RELATED SPECIES. 

By C. L. Shear, Pathologist, and Neil E. Stevens, 1 Pathologist, Fruit-Disease 
Investigations, and Ruby J. Tiller, Scientific Assistant, Office of Investiga- 
tions in Forest Pathology. 



CONTENTS. 



Page. 

Taxonomy 1 

Introduction 1 

The genus Endothia 3 

The species of Endothia 13 

Morphology and development 22 

Mycelium 22 

Stromata 23 

Spore measurements 30 

Physiology 36 

Cultural studies 3<3 



Physiology— Continued . 

Distribution of the species of Endothia. . 

Discovery of Endothia parasitica in 
China 

Discovery of Endothia parasitica in Japan 

Present distribution of Endothia para- 
sitica in America 

Host relations of the species of Endothia . 

Summary 

Literature cited 



TAXONOMY. 

INTRODUCTION. 

The discovery of a serious canker of the chestnut in the New York 
Zoological Park in 1904, by Merkel (49), 2 first attracted the atten- 
tion of pathologists and foresters to what has proved to be one of 
the most serious epidemics of a plant disease ever known in this 
country. 

The fungus which was found associated with these cankers (PI. 
I and PL II, fig. 1) and soon demonstrated experimentally to be 
their cause was described by Murrill (57) in 1906 as a new species 
of Diaporthe (D. parasitica). Search for the fungus in other places 
in New York and vicinity soon showed that it was already estab- 
lished and apparently rapidly spreading. Investigations which 
have been continued and extended from year to year have shown 

1 Formerly Pathologist, Office of Investigations in Forest Pathology 

2 Serial numbers in parentheses refer to " Literature cited," at the end of the bulletin. 
Note.— This ; bulletin is of value to botanists, especially plant pathologists and mvcolo- 

gists, and to all persons who are interested in the study of chestnut blight. 
43737° — Bull. 380 — 17 1 






2 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

conclusively that the disease is spreading very rapidly, especially 
west and south from New York and also north and east. 

The exact identity and relationships of the fungus causing the 
disease and the origin of the epidemic soon became the subject of 
study by various mycologists and pathologists. Different explana- 
tions were offered for the sudden appearance and behavior of the 
disease, one view being that the fungus was probably a foreign 
parasite which had been introduced: another, that the organism was 
probably a native species which had recently attracted attention, 
chiefly by reason of the weakened condition of the chestnut trees 
due to abnormal climatic or other conditions. 

In attacking the problem of the origin of the parasite and its pos- 
sible control, it was evidently necessary to secure all the information 
possible in regard to its life history, identity, distribution, and re- 
lationships. The senior writer in an unpublished paper prepared in 
1908 pointed out the close relationship and possible identity of 
J>'niju>rflic parasitica with certain species of Endothia. Clinton (16) 
and Farlow (-28) soon after also made the same suggestion. Two 
species of Endothia had already been described from this country 
by Schweinitz (74) under the old generic name, Sphaeria. These, 
however, had in recent years been regarded as a single species and 
referred to Endothia gyrosa (Schw.). Owing to a lack of knowledge 
of the types of these two species and for want of good specimens 
showing ascospores, it was difficult to determine what species of 
Endothia were indigenous in the eastern United States. Since it 
had been suggested that Diaporthe parasitica was either identical 
with one of Schweinitz's species or a mere variety of it, the present 
writers undertook a thorough study of the genus Endothia in its taxo- 
nomic, ecological, and pathological relations. It was first necessary 
to determine the identity of the two species already described by 
Schweinitz from America and also to learn their distribution and 
host relations. As one or both of Schweinitz's species were reported 
to occur in southern Europe on chestnut, it was important to obtain 
exact knowledge in regard to the identity and relationships of the 
European species. The senior writer spent several months in Eu- 
rope collecting material of Endothia in the field and studying her- 
barium specimens of types and authentic collections of Schweinitz 
and other authors. Material was also acquired by collection and 
exchange with pathologists and mycologists in nearly every region 
of the world in which Endothia was known to occur. Comparative 
cultural studies were made of all the living material secured, as well 
as inoculation experiments on various hosts. The recent discovery of 
the typical chestnut-blight parasite, Endothia parasitica, by Meyer 
(27, 76, 78), in China and Japan and the failure to find in Europe or 
America any native form which w T ould produce the disease appear 
to settle beyond question its foreign origin. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 3 

The present paper presents the results of several years' field and 
laboratory study of the species of Endothia. This includes the study 
of practically all the herbarium material of this genus preserved in 
the principal herbaria of Europe and America ; also field and lab- 
oratory studies of over 600 new collections from various localities 
and hosts in America, Europe, and Asia. Over 4,000 cultures have 
been studied and about the same number of inoculations made. 
These studies include the systematic relations of the species of 
Endothia and their physiological behavior on various culture media 
and under various conditions of light, moisture, and temperature; 
also inoculation experiments with the various species on various hosts. 

The writers wish to record here their- grateful acknowledgment 
and thanks for opportunities to examine specimens and for assistance 
rendered by various mycologists and pathologists and directors and 
curators of botanical gardens and museums, especially the following: 
Prof. O. Comes, Naples; Prof. Eomualdo Pirotta, Prof. Giuseppi 
Cuboni, and Drs. E. Pantanelli and L. Petri. Rome; Prof. P. Bac- 
carini, Florence; Prof. P. A. Saccardo, Padua; Dr. G. Briosi, Pavia; 
Dr. J. Briquet, Delessert Herbarium, Geneva; M. G. Beauverd, 
Boissier Herbarium, Geneva; Prof. L. Jost, Strasburg; Prof. W. 
Pfeffer, Leipzig; Dr. G. Lindau, Berlin; Dr. J. W. C. Goethart, 
Leiden; Prof. H. O. Juel, Upsala; Dr. P. Hariot, Paris; Sir David 
Prain, Kew ; Dr. A. B. Eendle, British Museum; Prof. P. B. Balfour, 
Edinburgh; Prof. T. Petch, Peredeniya, Ceylon; Dr. C. Spegazzini, 
La Plata, Argentina; Dr. TV. G. Farlow, Harvard University; Dr. 
W. A. Murrill, New York Botanical Garden ; Mr. Stewardson Brown, 
Philadelphia Academy of Science; Dr. G. T. Moore, St. Louis 
Botanical Garden; Prof. E. Bethel, Denver, and Drs. G. P. Clinton, 
P. J. Anderson, and F. D. Heald. The writers have also received 
specimens and cultures from numerous other colleagues which have 
been of great assistance and are duly appreciated. 

THE GENUS ENDOTHIA. 

The genus Endothia was established by Elias Fries in 1849 (33, 
pp. 385-38G), as follows: 

(X. Endothia. Fr.*) 

* Colore rubro fulvove, habitu Tuberculariae, peritheciis cellulosis difformi- 
bus pallidis, ascis diffluentibus, facile distinctum genus, nobis exoticum, sed 
jam in Europa australi obvium v. c. Sph. gyrosa Schw.— et subgenus, tuber- 
culo uniloeulari, sistit S. Tnbercularia Dec. Omnium horum generum char- 
acters proxime plenius exhibeamus, examinatis multis speciebus exoticis. 

The description of the genus transcribed here was published as 
a footnote in the work cited and was evidently based on the specimens 
contained in Fries's herbarium at the time the book was written, 



4 BULLETIN 380, U. S. DEPAETMENT OF AGRICULTURE. 

Fries (31, p. 73) had at that time, according to his own statement, 
authentic specimens of Sphaeria gyrosa sent him by Schweinitz and 
also the specimens collected by Guepin and Levieux in France, 
which he identified as this species. In Fries's herbarium at Upsala 
at present are found specimens of true S. gyrosa Schw. with 
Schweinitz's autograph label, but no specimens of S. gyrosa could 
be found attributed to Guepin or Levieux. There is a small packet 
marked " Sph. gyrosa" apparently in Fries's handwriting, but 
there seems to have been some confusion in the labeling or mounting 
of this specimen, as a small stroma of Ilypoxylon annulatum which 
does not look at all like Endothia is included. The other piece 
consists of an irregular pycnidial stroma which may be the southern 
European specimens referred to in the description quoted. Fries's 
identification of this European material as E. gyrosa was apparently 
based chiefly upon its superficial resemblance to the pycnidial 
stromata of Schweinitz's American specimens. The senior writer has 
seen and made a careful microscopic examination of a specimen col- 
lected by Guepin in France and preserved in De Notaris's herbarium 
at Rome. It is labeled "Sphaeria gyrosa Fries, Guepin, Angers." 
The specific name " gyrosa " has been crossed out by De Xotaris 
and " radicalis Schw." written above it and the date " April, 1845," 
added. This appears to be a part of the same collection that 
Guepin sent to Fries, as the specimen agrees well with Fries's 
description and consists chiefly of pycnidial stromata which are 
rather larger than is usual for Sphaeria radicalis and show con- 
siderable superficial resemblance to the stromata of Sphaeria gyrosa 
Schw. A thorough examination of this specimen, however, reveals 
a few perithecia and ascospores, which leave no doubt that it is 
S. radicalis of Schweinitz, as indicated by De Notaris on the label. 
What the plant sent Fries by Levieux was is unknown, as no speci- 
men so labeled could be found in Fries's herbarium. It appears 
from all the evidence at hand that Fries was mistaken in his identi- 
fication of the material from Levieux and Guepin, as no specimens 
of the true Sphaeria gyrosa Schw. have yet been seen from Europe. 
There seems to be no doubt, however, that Fries intended the true 
Sphaeria gyrosa Schw. to represent the type of his genus Endothia, 
as he had a part of Schweinitz's original collection at the time and 
never definitely placed any other species in the genus; hence, 
Sphaeria gyrosa Schw. should be adopted as the nomenclatorial 
type of the genus. It is clear from Fries's writings and specimens 
that he knew Sphaeria radicalis Schw., as he had American speci- 
mens from Schweinitz as well as European collections at the time 
he founded this genus. He did not, however, apparently regard it 
as congeneric with S. gyrosa. His specimens of S. radicalis show 



ENDOTHIA PARASITICA AND RELATED SPECIES. 5 

the typical perithelia with necks, whereas no perithecia have been 
found in any of Schweinitz's specimens of JS-. gyrosa examined by 
the writers. Fries, in common with Schweinitz, regarded the pyc- 
nidial cavities of S. gyrosa as perithecia. When the pycnidia of S. 
gyrosa are mistaken for perithecia and compared with the real 
perithecia of S. radicalis the differences appear marked. It was 
therefore quite as natural for Fries to place the two species in 
different genera as it had been for Schweinitz to place them in dif- 
ferent tribes of the genus Sphaeria. Fries's mistake in describing 
as perithecia the pycnidial cavities in the stroma of S. gyrosa ex- 
plains his reference to the asci as " ascis diffluentibus." Believing 
that he had perithecia but finding no asci, he interpreted this as 
indicating that they had disappeared. 

According to the plan of accepting only names originally applied 
to the ascospore stage, this name would be invalid, as proposed by 
Fries, and would be attributed to De Notaris, who placed the peri- 
thecial form of Sphaeria radicalis Schw. in the genus and described 
the ascospores. There is not the slightest question, however, in 
regard to the identity of the different stages of this fungus and 
their genetic connection, and the name Endothia has been almost 
invariably applied to these two species in both stages. 

SYNONYMY. 

There are only two true generic synonyms of Endothia: En- 
dothiella Saccardo, 1906 (71, p. 278) and Calopactis H. and P. 
Sydow, 1913 (81, p. 82). Endothiella was based on Endothiella 
gyrosa Sacc, which, according to authentic specimens from Saccardo, 
is undoubtedly the pycnidial form of Endothia -fluens as found in 
Italy. Calopactis was based on C. singularis, the pycnidial condi- 
tion of Endothia singularis (H. and P. Syd.) S. and S. Ascospore 
cultures of this have not yet produced any pycnidia, but the proof 
of the genetic connection of the two stages appears rather con- 
clusive from the occurrence of pycnidia and perithecia in the same 
stroma, as shown in Plate XII. Perithecial stromata and ascospores 
were also found in the specimen of the Sydow exsiccati in the Patho- 
logical and Mycological Collections of the Bureau of Plant Industry. 

Von Hohnel (43, p. 1479-1481) considers Cryphonectria Sacc. as a 
synonym of Endothia, taking C. gyrosa (B. and Br.) as the type of 
that genus because it is the first species listed by Saccardo in con- 
nection with his description of the genus. Saccardo, however, had 
previously established Cryphonectria as a subgenus, with C. abscon- 
dita as the type, which is not an Endothia. Valsonectria is also con- 
sidered by Von Hohnel a synonym of Endothia, but apparently he had 
not compared specimens of Spegazzini's fungus, which is found upon 
examination of the type species to be separate from Endothia. The 



6 BULLETIN 380, U. S. DEPAKTMENT OF AGRICULTURE. 

Tulasnes (83, p. 87-89) do not appear to have regarded Endothia as 
distinct from Melogramma, to which they referred E. gyrosa. The 
type of Melogramma, however, is M. melogramma (Bull.), which has 
a somewhat similar stroma, but the ascospores are 3-septate and dark 
colored and the perithecia not separable from the stroma, while the 
pycnospores are long, slender, and curved. 

STUDY OF EARLY COLLECTIONS AND TYPES. 

There has always been more or less uncertainty in regard to the 
identity of the older species of this genus of fungi. In order to get 
more light on this subject, a thorough study of all the available ma- 
terial in the way of literature, type specimens, and manuscripts was 
made. The first species to be described in this country was Sphaeria 
gyrosa Schw. This was collected by Schweinitz at Salem, N. C, and 
published in 1822 (72, p. 3). 1 Two hosts were given in the original 
description, Fagus and Juglans. 

As Schweinitz's description was prepared before the advent of 
careful microscopical studies and spore measurements, it is impossible 
to identify the organism satisfactorily from the original description. 
It was, therefore, important, if possible, to locate the type specimens 
upon which the description was based. Schweinitz's herbarium was 
left at his death, in 1834, to the Philadelphia Academy of Science. 
His specimens of fungi at the time they were transferred to the acad- 
emy were contained in small, folded paper packets, as shown in Plates 
V and VI. These packets were then inclosed in other heavy paper 
wrappers, folded to small quarto size, and three or four of these large 
packets, each bearing a manuscript list of the species contained, were 
then inclosed in quarto pasteboard covers, tied with tape. The in- 
dividual species packets were labeled in Schweinitz's handwriting, 
with the name of the species and the locality of the collection, as 
shown in Plate V, figure 2. 

These species packets frequently bore the names of several locali- 
ties, but usually two, Salem [N. C] and Bethlehem [Pa.], as most of 
his collecting was done at these places. This fact, in addition to the 
evidence afforded by the specimens in the packets, clearly indicates 
Schweinitz's method of handling his specimens. 

Frequently some of the specimens in a packet show the remains of 
a gummed strip. This will be noticed in Plate III, which indicates 

1 24. Sphaeria <nir<if<a Sz. 

8. 8tibperipherica minor gregaria subconfluens aurantio miniata, sphaerulis gyrosis farc- 
1 is demum prominulis pulverulentis, stromate lutescenta. 

In cortice nnndum eorrupto etiarn vivo Fagorum et Iuglandurn. Junior planiuscula, ubi 
adolevit sistit corpus subrotundum, tuberculis minimis et magoribus asperum et gyrosum. 
Sphaerulae farctae, terotes, supra gyrosae, paucae, radiatim divergentes a superficie ad 
centrum fere stromatis continuantur, primuru sublantes, demum prominulae, cortice pul- 
verulento ; ipsum tamen centrum farinacea carne componitur. Gelatina asciphora albet. 
Ostiola indistineta. — Transitum facit ad Sphaerias septimae divisionis. 



ENDOTHIA PARASITICA AND EELATED SPECIES. 7 

that at one time the specimen was apparently attached to a sheet 
by a gummed paper strip. This seems to have been the way in which 
Schweinitz originally mounted his specimens, but later, apparently, 
he changed to the plan of putting them in paper packets and removed 
those which had been attached to sheets. It is clear from an examina- 
tion of the specimens still ■ found in some of the original packets 
that two or more different hosts were sometimes included. In some 
cases as many as four or five different collections appear to have been 
placed in the same packet and each new locality added on the out- 
side. This method of keeping specimens makes it rather difficult in 
some cases to determine which belongs to the first collection. In the 
case of S phaeria gyrosa but two localities are indicated on the packet, 
Salem and New England. (See PL VI, fig. 2.) 

The difficulties in determining the true type specimen of any 
species would have been sufficiently great if the collection had been 
preserved as it was left by Schweinitz. The matter is, however, 
further complicated by the later handling and rearrangement of the 
collection. Some time after Schweinitz's death (the exact date the 
writers have been unable to determine) his collection of fungi was 
more or less completely rearranged and mounted. The greater part 
of this work was evidently done by Dr. Ezra Michener. Dr. Mich- 
ener was a lifelong resident of Chester County, Pa. He early be- 
came interested in botany, and in 1840 was elected a correspondent 
of the Philadelphia Academy of Natural Science. He paid special 
attention to the collection and study of fungi and corresponded and 
exchanged with various mycologists, especially Curtis and Ravenel. 
He left a large collection of fungi, which the writers have recently 
had the privilege of examining. Among his specimens are found 
many labeled "Ex. Herb. Schw."', which are undoubtedly part of 
Schweinitz's original collections at the Philadelphia Academy. 
These specimens, as well as all of Michener's fungi, are mounted in 
exactly the same manner as the mounted portion of Schweinitz's col- 
lection at the Philadelphia Academy. The mounting paper, the 
specimen slips, the arrangement, manner of attachment, and the 
handwriting on the labels are identical, as will be readily perceived 
by comparing the illustrations from photographs of sheets from 
both herbaria. It is, therefore, clear that the mounted collection 
of Schweinitz's herbarium was prepared by Dr. Michener. He evi- 
dently took from Schweinitz's original paper packets what appeared 
to him to be the best or most typical specimen of the species in the 
packet and attached it with glue to a square slip of paper, as shown 
in Plate III. Where there was but little material in the original 
packet it was all mounted in this manner. In case there were several 
pieces in the original packet he used his own discretion in making 
the selection of the part to be mounted and the part to be left. 



8 BULLETIN 380, U. S. DEPARTMENT OP AGRICULTURE. 

When there were included in the original packet specimens from 
different hosts or different localities, in some cases representing dif- 
ferent species, it would have been difficult, if not impossible, to de- 
termine which was the original material from which Schweinitz's 
description was made. At the same time, Dr. Michener, in case the 
specimen was not too scanty, evidently took a small portion of it 
for his own herbarium. Michener's catalogue of his herbarium lists 
Sphaeria gyrosa Schw. Consulting his collection it is found that 
Xo. 1431, the number of Schweinitz's specimen, is missing. Pin 
holes in the mounting sheet, however, show that the specimen which 
was once there has been removed. As perhaps throwing some light 
on the possible location of this specimen, it may be said that a speci- 
men apparently typical S. gyrosa, pycnidial form on beech, labeled 
by Dr. William Trelease as Sphaeria gyrosa from Pennsylvania, was 
seen in the Boissier Herbarium, Geneva. Dr. Trelease tells the 
writers that this specimen probably came from Dr. Michener, and 
as there is no evidence that Dr. Michener or any one else has col- 
lected E. gyrosa in Pennsylvania there is considerable probability 
that this specimen represents a portion of Schweinitz's original col- 
lection. 

In most cases all of the material in Schweinitz's original species 
packets was removed and either mounted or distributed. This was 
the case with Sphaeria gyrosa. The original packet of Schweinitz, 
which was fortunately preserved with all the others, is empty and 
apparently a part at least of the specimen which it contained is 
found in the mounted collection as prepared by Michener. This 
consists of a single piece of bark shown in Plate VI, figure 1. From 
the evidence the writers have been able to gather from Schweinitz's 
manuscripts and correspondence, as well as from studies of his writ- 
ings and specimens in other herbaria, it appears that this specimen 
is the one indicated on the original packet and also by Schweinitz 
(74, p. 206) as having been collected in New England and sent to 
him by Torrey. This, as shown- by his correspondence, was after he 
had left North Carolina. The bark upon which the fungus grew is 
clearly not Fagus, Juglans, or Quercus, the hosts originally given for 
S. gyrosa, but apparently Acer. It is therefore not a part of the 
original specimens from Salem, N. C, upon which his description 
was based, and in reality is not Sphaeria gyrosa, but a species of 
Neetria, which Schweinitz incorrectly identified as S. gyrosa. Por- 
tions of this same specimen are found in Berkeley's herbarium at 
Kew and in the Curtis herbarium at Harvard. They are clearly the 
Neetria referred to above from Torrey. In this connection, it may 
be noted that E. Hitchcock in 1829 (42, p. 63) reports Sphaeria 
gyrosa Schw. from Amherst, Mass., and states in the preface to his 
list that Dr. Torrey assisted in the determination of the cryptogams. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate 







"Cankers" Caused by Endothia parasitica on Castanea dentata. x V 2 . 



Bui. 380, U. S. Dept. of Agriculture. 



Plate II. 






ML* 



HERB. mus. PARIS 






!«•/ '<,,, 



^V 



( Ex. herb. Ad. Brongaian. Anno 1843 ,'. 



y 



Fig. 1.— Perithecia and Pycnidial Stromata of Endothia parasitica with Cankers 
on Castanea dentata. Fig. 2.-Cotype of Sphaeria gyrosa Schw. on Fagus. 

Specimen new in the Paris Museum sent to Brongniart by Schweinitz, showing Tulasne's label 
Metogramma gyrosum" and Schweinitz's autograph label. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate III. 




A Sheet from the Mounted Portion of Schweinitz-s Herbarium at the 

PHILADELPHIA ACADEMY OF SCIENCES, SHOWING SPECIMENS AS PREPARED AND 

Labeled by Michener. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate IV. 



**/ 




■''■- 




A Sheet from Michener'S Herbarium, Showing a Part of Schweinitz-s Type 
of Peziza cinnabarina (Upper Right Hand Corner); Also Showing Clearly 
That the Mounting and Labeling of This and Schweinitz-s Collection Were 
Done by the Same Person. 



ENDOTHTA PARASITICA AND RELATED SPECIES. 9 

This seems to explain the origin of the specimen which Schweinitz 
received from Dr. Torrey. The writers have searched in vain for 
Endothia gyrosa in Amherst and vicinity and they know of no col- 
lections of the fungus from Massachusetts. No specimens upon 
which Hitchcock's list was based have been located. 

Since it can be clearly shown that little or none of the original 
type collection of this species is in the Philadelphia Academy col- 
lection it must be looked for elsewhere. It is found by reference to 
Schweinitz's correspondence and manuscripts, which have been care- 
fully examined by the writers through the courtesy of the Phila- 
delphia Academy and the descendants of Schweinitz, and also by 
studies in foreign herbaria that he divided his specimens with many 
of his European and American correspondents. As he does not ap- 
pear to have kept any duplicates separate from his regular collection 
it seems probable that the specimens he distributed were taken from 
the original packets. Thus in some cases, apparently all of a type 
specimen was removed from the original packet. In fact, in one 
instance (73, p. 5) he states that he sent his only specimen of a 
species of Hypoxylon to Dr. Schwaegrichen, of Leipzig. 

It seems rather certain from statements made by Schwaegrichen 
in his introduction to Schweinitz's paper on the fungi of North 
Carolina (72) that specimens of a large number, if not all, of the 
species represented in that work were sent to him. The types or 
parts of the types should therefore be found in Schwaegrichen's 
herbarium. In spite of all their efforts, however, through correspond- 
ence and personal search in Europe, the writers have been unable 
to locate Schwaegrichen's collection of fungi. They found, however, 
in the herbarium of the University of Leipzig a small bit of a speci- 
men labeled "Sj)haerm gyrosa Schwein. Juglans Fagus Carolina 

D. Schwaegrich. dd 5-21 K. Z." This specimen is evidently a part 
of the original collection of Schweinitz which was sent to Schwaeg- 
richen and given by him to Dr. Kunze. The host is apparently 
neither Juglans nor Fagus, but seems to be Quercus. It may be 
noted in this connection that in spite of diligent search by the 
writers and various other collectors no specimen of Endothia has 
yet been found on Juglans in this country. Neither have the writers 
been able to find any specimen in the various herbaria examined. 
They have concluded, as a result of their studies, that the mention 
of Juglans by Schweinitz was an error in the identification of the 
host, which it is believed was really Quercus, the host upon which 

E. gyrosa is most frequently found in the South, and especially in the 
vicinity of Salem. According to the American Code, 1 however, the 
specimen which should be taken as the type in this case is the one on 



1 American Code of Botanical Nomenclature. Canon 14, b. Bulletin, Torrey Botanical 
Club, vol. 34, p. 172. 1907. 



10 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

Fagus, as this is the first-mentioned host in the original description. 
No specimen of this species on Fagus from Schweinitz was found in 
Kunze's collection. However, authentic specimens from Schweinitz 
on Fagus have been found in Fries's herbarium at Upsala, in 
Hookers herbarium at Kew, and in Brongniart's herbarium in the 
Paris Museum. The last, which is the largest and best specimen, 
is shown in Plate II, figure 2. Microscopic studies of the specimens 
at Paris and Kew show only pycnidia with pycnospores. The writers 
were unable to examine microscopically the specimen in Fries's herba- 
rium, but it agreed in all macroscopic respects and also, so far as 
could be determined with a hand lens, with the Paris and Kew speci- 
mens. These specimens agree with all the material collected on Fagus 
from various localities in the South. Studies of numerous collec- 
tions of E. gyrosa have shown that the pycnidial form can be dis- 
tinguished with certainty from any of the other species of Endothia 
at present known. The connection between this pycnidial form and 
the perithecial form as described has been demonstrated by pure 
cultures from ascospores and also by the association of typical 
pycnidia and pycnospores with perithecia and ascospores in the 
same stroma. There appears to be no reasonable doubt, therefore, 
that the specimens collected by Schweinitz on Fagus were the 
pycnidial form of Endothia gyrosa, and the specimen in the Paris 
Museum which was sent by Schweinitz to Brongniart about 1825 
may properly be considered a cotype of Schweinitz's species. The 
specimen from Schweinitz in Kunze's herbarium at Leipzig also 
proves on microscopic examination to be the pycnidial form of the 
same fungus. It is probable from the evidence at hand that 
Schweinitz did not collect any specimen showing ascospores of this 
fungus. However, the specimen in Kunze's herbarium shows some 
perithecia evidently immature and without spores. A part of the 
specimen from Schweinitz in Fries's herbarium shows stromata on a 
piece of bark, evidently not Fagus, but probably Quercus. This 
also appears to be pycnidia only. 

The specimen referred to by Clinton (18), which was found in 
the original packet of Schweinitz at Philadelphia with Sphaeria 
enteromela, is also undoubtedly the pycnidial form of E. gyrosa, 
which closely resembles some early stages in the development of 
species of Hypoxylon, especially II. enteromela. These species 
may be easily confused with each other, and this would seem to be a 
probable explanation of the accidental presence of this specimen in 
this packet. Another point of interest in this connection is the fact 
that in spite of diligent search on the part of the writers and many 
other collectors and an examination of numerous specimens of En- 
dothia on Fagus in all stages of development and from different 
localities only Endothia gyrosa has been found on this host. Of 



ENDOTHIA PARASITICA AND RELATED SPECIES. ll 

course, it can not be positively stated that E. fluens does not occur 
on Fagus in this country, but if it does it must be rare. In this con- 
nection, it is also perhaps worthy of note that, notwithstanding the 
mention of Fagus as a host in Europe, the writers have never seen 
any European specimens of Endothia on this host. The specimens 
so named by Roumeguere and distributed as No. 989 Fun. Gal. on 
beech are, according to several specimens examined, evidently a 
young condition of some Hypoxylon, probably H. coccineum, which 
in this state bears a superficial resemblance in form and color to the 
stromata of Endothia, but can be easily distinguished by the dark- 
brown or blackish color of the interior of the stroma. The identity 
of Schweinitz's Sphaeria gyrosa with the long ascospore form of 
Endothia shown on Plate VII is based on careful microscopic 
study of the stromata and measurement of the pycnospores from 
four specimens of the original collections of Schweinitz in North 
Carolina, three on Fagus and one labeled Juglans. The three on 
Fagus show the typical pycnidial stromata and pycnospores of the 
species, either of which is sufficient for positive identification when 
thoroughly known. The specimen referred to by Schweinitz as on 
Juglans also shows typical pycnospores of E. gyrosa. The evidence, 
as stated above, leaves no reasonable doubt as to the identity of the 
fungus which Schweinitz described as Sphaeria gyrosa. 

According to a specimen which is probably a portion of Schwei- 
nitz's t}^pe found in Michener's herbarium, Peziza cinnabarina 
Schw. is the pycnidial form of E. gyrosa (Schw.) (See PI. IV.) 
It is the form with small pycnidia on bare wood of Liquidambar. 
This was first reported by Schweinitz as " Peziza flammea A. and S." 
and later changed as above. Later Saccardo (69, vol. 8, p. 399), 
thinking that this was a Discomycete, transferred it to the genus 
Lachnella. 

The other American species of Endothia which was described by 
Schweinitz as Sphaeria radicalis and first published by Fries in 1828 
(31, p. 73) has also until recently been more or less misunderstood. 
The only specimens of this species found at present in Schweinitz's 
mounted collection at the Philadelphia Academy of Science is a 
small piece of bark of an oak root bearing a few pycnidial stromata. 
No host was given in Fries, but Schweinitz in 1832 (74 p. 197) gives 
Fagus as the host. That this was an error and that the host was 
really Quercus and not Fagus is clearly indicated by all of Schwei- 
nitz's specimens examined, not only those in the Philadelphia 
Academy but those found in several herbaria in Europe and one in 
Curtis's herbarium at Harvard, and also in Schweinitz's autograph 
label on the original packet in his herbarium. A photograph of this 
packet is shown in Plate VI. 

The description of this species was first published by Fries in 
1828 (31. p. 73). Schweinitz's specimen at the Philadelphia Academy 



12 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

shows only pycnidia. (See PI. V, fig. 2.) His description, how- 
ever, as well as his unpublished illustrations preserved in the library 
of the Academy, show clearly that perithecia were present in the 
material from which the description was made. This is also con- 
clusively shown by authentic specimens from Schweinitz in at least 
two European collections, those of Fries at Upsala and Hooker at 
Kew. A microscopic examination of these specimens shows good 
perithecia and mature ascospores having the characters and meas- 
urements given elsewhere in this paper for Endothia fluens (Sow.). 
(See PI. XVII, fig. 9.) As there is no indication in Schweinitz 's 
writings or in his manuscript notes and records that he made more 
than one collection of this species, there is no reason to doubt that 
the material at Upsala and Kew is a part of that upon which he 
based his description of Sphaeria. radicalis Schw. The true type 
specimen of the species is that in Fries's herbarium upon which he 
based his description, which was added to the diagnosis sent by 
Schweinitz. 

One year after the description of this species from America it 
was reported from Italy by Rudolph, in 1829 (66, p. 393), and in 
1830 Fries (32, p. 511) himself reports the fungus from France. 
This species had, however, been collected and described before 
in its pycnidial condition in 1814 by Sowerby (79, pi. 438) under 
the name of Sphaeria flueus. This was reported in 1836 by Berkeley 
(8, p. 254) as Sphaeria gyrosa Schw. A microscopic study of the 
original material of this species, which was collected by Charles 
Lyell on chestnut in the New Forest in southern England and is 
now preserved in the Kew Herbarium, leaves no doubt that it is 
the pycnidial form of Endothia radicalis (Schw.). Plate XVII, fig- 
ure 3, shows pycnospores from Sowerby's specimen at Kew. This 
specimen agrees with Sowerby's illustration and is apparently the 
one from which this figure was made. The pycnospore masses 
are somewhat larger than usual; otherwise it is typical of E. radi- 
calis Schw. 

At first it did not seem possible to distinguish the species of 
Endothia in their pycnidial condition, but thorough microscopic 
studies of large quantities of material in the field and laboratory in 
both America and Europe have shown that the two sections of the 
genus and some of the species can usually be separated with cer- 
tainty in this stage of their development, as indicated by the tables 
of measurements and in the photographs of pycnospores, and es- 
pecially by the stromata of the different species. 

The first description of the ascospores of E. radicalis was given 
in 1858 by Currey (21, p. 272), who examined the specimens from 
Schweinitz in Hooker's herbarium at Kew. Currey figured what 
he believed to be four ascospores. Two are apparently typical E. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 13 

fluens; the other two are more than 1 -septate and belong to some 
other organism. Cesati and De Notaris, in 1863 (11), first definitely 
referred Sphaeria radicalis Schw. to Endothia. Up to this time 
Sphaeria gyrosa and Sphaeria radicalis were generally regarded by 
mycologists as separate species and were placed by Schweinitz and 
Fries in different groups of the genus Sphaeria, though they both 
mention a similarity in external appearances. 

In 1863 the Tulasnes, in their epoch-making work on the fungi 
(83, pp. 87-89), made a careful microscopic study of the specimens 
from Schweinitz preserved in the Paris Museum and also specimens 
received from De Notaris, Berkeley, and other collectors. At that 
time no ascospores of /Sphaeria gyrosa had apparently been described 
by mycologists. The material of S. gyrosa from Schweinitz which 
the Tulasnes found in the Paris Museum included the specimen on 
Fagus which had been sent by Schweinitz to Brongniart. There 
seems to be no evidence that the Tulasnes examined other specimens 
from Schweinitz or that they examined any specimens showing asco- 
spores of the true Sphaeria gyrosa. This is indicated by their de- 
scription and measurements of the ascospores. From their studies of 
Schweinitz's specimens and from other Carolina specimens sent them 
by Berkeley they concluded that Sphaeria gyrosa and Sphaeria radi- 
calis are the same species and called it Melogramma gyrosum. 

Fries (33, pp. 385-386) had earlier (1819) reported Sphaeria gyrosa 
as occurring in southern Europe. This report was apparently based 
upon specimens of pycnidial stromata of E. fluens, somewhat larger 
and more irregular in shape than usual, collected in western France 
by Guepin and Levieux and already referred to. 

The statement of the Tulasnes (83, pp. 84—89) in regard to the 
identity of these species was accepted by practically all mycologists 
down to 1912, when the discussion in regard to the origin and 
relationships of Endothia parasitica commenced. Ellis and Ever- 
hart in 1892 (26, p. 552) apparently figured the true E. gyrosa Schw. 
but cited exsiccati of both E. gyrosa and E. fluens and gave the 
ascospore characters and measurements of E. fluens, apparently 
copied from Winter (85, p. 803), as the spores figured do not agree 
with the description. 

THE SPECIES OF ENDOTHIA. 

ENDOTHIA Fries, 1849. Sum. Veg. Scand., p. 385. 1 

Synonyms : 

Endothiella Sacc, 1906, in Ann. Mycol., v. 4, no. 3, p. 273. Type species, 

E. gyrosa Sacc, 1 c. 
Calopactis H. and P. Syd., 1912, in Ann. Mycol., v. 10, no. 1, p. 82. Type 

species, C. singularis, 1 c. 

1 All references to literature in synonymy are given in full in " Literature cited," p. 77. 



14 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

Stromata subcorticular in origin, variable in size and shape, 
pustular to subspherical, subcoriaceous to friable, sometimes con- 
fluent, surface light auburn 1 or chestnut to mahogany red, capucine 
yellow or cadmium orange to scarlet within ; pycnidial and peri- j 
thecial stromata the same or similar; pycnidia few to numerous, con- 
sisting of simple cavities or complex and irregular chambers; 
pycnospores minute, simple, bacilliform to oblong, yellowish to 
reddish in mass; perithecia deeply immersed, in one or more irregu- 
lar layers, usually black when mature, with long necks, black 
within, colored like the stroma without ; asci clavate to oblong fusoid, 
8-spored, usually without paraphyses; ascospores oblong fusoid or 
subellipsoid to cylindric or allantoid cylindric, uniseptate or non- 
septate, hyaline to pale yellowish. 

Section 1. — Ascospores short cylindric to allantoid, continuous or 
pseudoseptate. 

ENDOTHIA GYROSA (Schw.) Fries, 1849, Sum. Veg. Scand., p. 385. p. p. 

Synonyms : 
Pycnidia : Sphaeria gyrosa Schw., 1822, Syn. Funs. Car. Sup., p. 29, no. 24. 
Peziza flammea Schw. (not. Alb. and Schw.), 1822, Syn. Fung. Car. Sup., 

p. 93, no. 41, p. p. ad Liquidambar. 
Sphaeria gyrosa Fries, 1822, Syst. Mycol., v. 2, p. 419. 
Peziza gyrosa Spreng., 1827, Syst. Veg., v. 4, pars. 1, p. 515. 
Peziza cinnabarina Schw., 1832, Syn. Fung. Am. Bor., p. 173. 
Melogramma gyrosum, L. R. and C. Tub, 1863, Selecta Fung. Carpob, t. 2, 

p. 87. p. p. min. 
Melogramma gyrosum M. A. Curtis, 1867, Cat. Indig. Nat. Plants, p. 143. 
EndotMa gyrosum (Tub) Fckb, 1869, Symb. Mycob, p. 226. 
Melogramma gyrosum Tub, Rav., 1879, Fung. Amer. Exs., no. 352. 
Lachnella cinnabarina Sacc, 1889, Syll. Fung., v. 8, p. 399. 
Perithecia : Sphaeria gyrosa Schw., Rav., 1852, Fung. Car. Exs., no. 49. 

Melogramma gyrosum Tub, Cooke, 1878, in Ann. N. Y. Acad. Scb, v. 1, no. 

5/6, p. 185. 
EndotMa gyrosa Fckb, Sacc, 1882, Syll. Fung., v. 1, p. 601. p. p. min. 
EndotMa gyrosa Schw., Ell. and Ev., 1887, No. Amer. Fung. Exs., no. 1956. 
EndotMa gyrosa (Schw.) Ell. and Ev., 1892, No. Amer. Pyren., p. 552, p. p. 
EndotMa radicalis (Schw.) Farb, Clint., 1912, in Science, n. s., v. 36, no. 

939, p. 908. 
Endothia radicalis (Schw.) Shear, 1912, in Phytopathology, v. 2, no. 5, p. 

211. 
Endothia radicalis (Schw.) Fries, P. J. and H. W. And., 1912, in Phyto- 
pathology, v. 2, no. 5, p. 210. 
Type specimen. — The type in Herb. Schw. is wanting. A cotype is in Herb. 
Museum of Paris. 

Pycnidia. — Stromata corticular or subcorticular, pulvinate to tubercular, 
rugulose, scattered or gregarious, occasionally confluent, 1.5 to 3 mm. in diame- 
ter by 1.5 to 2 mm. high, orange chrome when young to chestnut when mature, 

1 In the following descriptions of cultures and elsewhere throughout this paper, the 
names of colors are taken from Ridgway's recent work on color nomenclature (64). 



ENDOTHIA PARASITICA AND RELATED SPECIES. 15 

becoming almost black when old and weathered, cadmium orange within; 
pycnidia consisting of numerous irregular labyrinthiform chambers in the 
stroma, separated by walls of varying thickness and opening by irregular pores 
in the surface of the stroma ; sporophores cylindric or slightly tapering toward 
the apex, 6 to 9 /*. long; pycnospores oblong, straight or sometimes slightly 
curved, appearing hyaline when separate, warm buff to ochraceous buff or 
darker, according to mass and moisture content, 3 to 4 by 1.5 to 2 n. 

Perithecia. — Stromata the same or similar to those producing pycnidia ; 
perithecia dark, membranous, few to many, mostly 25 to 50, usually arising 
in the lower portion of the stroma, 150 to 300 n in diameter, very irregularly 
arranged in one to several layers, prolonged into slender necks which penetrate 
the stroma above and sometimes protrude somewhat, terminating in a short 
conical ostiole ; asci oblong fusoid or subclavate, very short stipitate, 25 to 30 
by 6 to 7 n ; ascospores irregularly biseriate, cylindric to allantoid, 7 to 11 by 
2 to 3 ^, mostly 7.5 to 10 by 2 to 2.5 fi, hyaline when separate, slightly yellowish 
in mass, with a very thin gelantinous envelope when mature. 

Cultural characters. — Cultures one month old on white corn meal show an 
abundant thick growth of mycelium producing irregular tubercular masses 
resembling pycnidial stromata, but without spores. The surface color is 
capucine buff. The medium usually changes to perilla purple. It is distin- 
guished from E. singnlaris, its nearest relative, by its more rapid growth and 
the formation of the large tubercular masses. 

Hosts. — Exposed roots and branches: Quercus alba, Q. eoccinea, Q. faleata, Q. 
georgiana, Q. ilieifolia, Q. imbricaria, Q. marylandica, Q. nigra, Q. phellos, Q. 
prinus, Q. rubra, Q. velntina, Q. virginiana, Liquidambar styraciflua, Fagus 
americana and F. sylvatica cult, vars., Castanea dentata and cult, vars., and 
Vitis sp. (25). 

A specimen of this species collected by Ravenel has the host given as maple 
(Acer), but microscopic examination shows it to be Liquidambar. 

Type locality. — Salem, N. C. 

Geographical distribution. — Southwestern Connecticut to central Michigan, 
southward to Florida and Texas ; also Kansas and California. 

Illustration s.— Ell. and Ev., 1892, No. Amer. Pyren., pi. 36, fig. 6S ; Clint. 
1913, in Conn. Agr. Exp. Sta. Rpt, 1911, 1912, pi. 28, fig. a, d, and g. 

Exsiccati. — Pycnidia: Baker, PI. Pac. slope, 722, on Querent agrifolia; Rav. 
Fung. Amer., 352, on Quercus. Perithecia : Ell. and Ev. No. Amer. Fung., 1956, 
on Quercus ; Rav. Fung. Car., 49, on Quercus and Liquidambar. 

ENDOTHIA SINGULARIS (H. and P. Syd.) S. and S. nov. comb. 

Synonyms : 
Pycnidia : Calopaetis singularis H. and P. Syd., 1912, in Ann. Mycol., vol. 10, 
no. 1, p. 82. 
Endothia gyrosa Ell. and Ev., in Herb. N. Y. Bot. Gard. 
Endothia gyrosa (Schw.) Fckl. H."hnel, 1913, in Sitzber, K. Akad. Wiss. 
[Vienna], Math. Naturw. Kl., Abt. 1, Bd. 122, Heft 2, p. 298. 
Type specimen. — H. and P. Syd., Fung. Exot, no. 88, on Q. gambellu. 
Pycnidia. — Stromata corticular, erumpent, depressed globose, sometimes ir- 
regular, scattered, or gregarious, 3 to 5 mm. wide by 2 to 4 mm. high, outer wall 
thick, coriaceous, becoming brittle, mahogany red without, scarlet within ; pyc- 
nidia consisting of innumerable nearly spherical cavities throughout the stroma, 
25 to 35 ix in diameter, the walls disintegrating into a powdery mass and the 
whole set free by the irregular rupture of the stroma wall, usually leaving a cup- 
like basal portion attached to the bark; sporophores, according to the Sydows, 



16 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

short, hyaline, subulate, 6 to 8 by 1 m; pycnospores ovoid oblong, hyaline, the 
contents of each pycnidial cavity adhering in a globular mass, when set free, 
3 to 4 by 1 to 1.5 fi. 

Perithecia. — Stromata the same or similar to those producing pycnidia ; 
perithecia membranous, few to many, usually 100 or more, 200 to 350 y. in 
diameter, irregularly arranged in several series, prolonged into slender necks 
which sometimes protrude from the stroma ; ostioles depressed conical ; asci, 
oblong cylindric or subclavate to fusoid, substipitate, 25 to 35 by 4.5 to 5.5 p ; 
ascospores irregularly biseriate, cylindric to allantoid, with a thin gelatinous 
envelope, hyaline when separate, slightly yellowish in mass, 7 to 11 by 1.5 to 
3 ii ; mostly 7.5 to 10 by 2 to 2.5 fi. 

Cultural characters. — Cultures one month old on white corn meal have a 
cadmium and orange to capucine buff mycelium. It is distinguished from 
E. gyrosa by its slower growth and brighter color and the want of tubercular, 
stromalike masses. No spores of this species have been produced in any of 
the writers' cultures. 

Hosts. — Quereus gambeUii, Q. leptophylla, Q. nitescens, Q. utahensis. Bethel 
also reports it on Q. pungens. 

Type locality. — Palmer Lake, Colo. 

Geographical distribution. — Colorado and New Mexico. 

Illustrations. — Pycnidia : H. and P. Syd., 1912, in Ann. Mycol., vol. 10, no. 1, 
p. 82, figs. 1-5. 

Exsiccati. — Pycnidia and perithecia: H. and P. Syd., Fung. Exot, 88, on 
Quereus. Pycnidia : Bart. Fung. Col., 4002, on Quereus utahensis. 

In shape and size of pycnospores and ascospores this species closely 
resembles E. gyrosa, but is easily separated by the much greater size 
of its stromata, its brighter color and very numerous, small, regular 
pycnrdial cavities and more numerous perithecia, as well as its geo- 
graphical distribution. 

The specimens of the Sydow exsiccati, No. 88, in the Pathological 
and Mycological Collections of the Bureau of Plant Industry show 
both pycnidia and perithecia. 

Section 2. — Ascospores oblong fusiform to oblong ellipsoid, uni- 
septate when mature. 

ENDOTHIA FLUENS (Sow.) S. and S. nov. comb. 

Synonyms : 
Pycnidia : Sphaeria fluens Sow., 1814, Col. Fig. Engl. Fungi, Sup. pi. 438, 
figs. 1, 2. 
Sphaeria gyrosa Berk., 1836, Brit. Fungi, p. 254. Not Schw. 
Endothia gyrosa Fries, 1849, Sum. Veg. Scand., p. 385. p. p. Europ. 
Sphaeria radicalis Fckl., 1861, Enum. Fung. Nass., p. 76, no. 640. 
Endothia gyrosutn Fckl., 1869, Symb. Mycol., p. 226. p. p. spec. cit. 
Endothia gyrosa (Schw.) Fckl., forma castaneae vescae Sacc, 1876, Mycol. 

Yen. Exs., no. 929. 
Endothiella gyrosa Sacc, 1906, in Ann. Mycol., v. 4, no. 3, p. 273. 
Perithecia : Sphaeria radicalis Schw., Fries, 1828, Elenchus Fung., v. 2, p. 73. 
Sphaeria radicalis Schw., Rudolphi, 1829, in Linnaea, Bd. 4, Heft 3, p. 393. 
Sphaeria radicalis Schw., Fries, 1830, in Linnaea, Bd. 5, Heft 4, p. 541. 



Bui. 380, U. S. Dept. of Agriculture. PLATE V 






* :-,r :• 



A-,,, +<■' , /■*<{■'* '■• /fat /</<e c'tc-.t-rtV,-* »>i .■<■ vvw^ 

1 



/? Cc _ /*// _- *Se/,7t ■ J"r 



sQ^/j?y _- ,yy/c . ^rt^to 




L '/, ■* -. , ~t*%£4t&i 






Fig. 1— Photograph of Schweinitz's Manuscript Notes, with His Description 
of Sphaeria radicalis.' Fig. 2.— Specimen of S. radicalis in the Mounted 
Collection of Schweinitz, as Prepared by Michener-, Also Original Packet 

WITH SCHWEINITZ'S AUTOGRAPH LABEL. 



Bui. 380, U. S. Dept of Agriculture. 



Plate VI. 



/ 4£/- %-#<$ -^St/rft . ±Yr , / c e~ 



Y 



J 








ee^^ec ay t r />^ /?&<?* ±st>/^<^, 



•y 



~/<?c £n>&-*^* . — *-^-\ /^W^- c. 



mfti . nmDifWa IBM 



fefc 









h 









i£ 



$3 

i 



Fig. 1.— Photograph of the Specimen in Schweinitz'S Herbarium Mounted by 
Michener. Not True Endothia gyrosa but a Nectria. Fig. 2.— Original 
Paper Packet in which Schweinitz'S Type Material of E. gyrosa was Pre- 
served, with His Autograph Label. 



Bui. 380, U. S. Dept of Agriculture. 



Plate VII. 




Endothia gyrosa Growing on the Recently Cut End of a Living Branch of 
Fagus sp. Natural Size. 



Bui. 380, U. S. Dept. of Agriculture. 



PLATE VIII. 




Mycelial Fans of Endothia parasitica under the Bark of Castanea dentata. 

Illustration from Heald (39), by courtesy of I. C. Williams, Pennsylvania State Forestry 

.Department. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 17 

Synonyms — Continued. 
Peritheeia — Continued. 

Sphaeria radicalis Schw., 1832, Fun. Am. Bor., p. 197. 

Sphaeria radicalis Schw., Mont., 1834, in Ann. Sci. Nat. Bot, s. 2. t. 1, 

p. 295. 
Sphaeria (Diatrype) radicalis Fries, Currey, lS. r >8, in Trans. Linn. Soc. 

London, v. 22, pt. 3, p. 272, pi. 47, fig. 89. p. p. 
Valsa radicalis Ces. and De Not., 1863, in Connn. Soc. Crittog. Ital., v. 1, 

p. 207. 
Endothia radicalis (Schw.) Ces. and De Not.. 1SG3. in Connn. Soc. Crittog. 

Ital., v. 1, opp. p. 240. 
Melogramma gyrosum L. II. and C. Tul., 1863, Selecta Fung. Carpol., t. 2, 

p. 87. p. p. max. 
Sphaeria (Diatrype) radicalis Schw., Currey, 1865, in Trans. Linn. Soc. 

London, v. 25, pt. 2, p. 244. 
Endothia gyrosa (Schw.) Fckl., Sacc, 1882, Syll. Fung., v. 1, p. 601. p. p. 
Endothia gijrosa var. rostellata Sacc, 1882, Syll. Fung., v. 1. p. 602. 
Endothia radicalis (Schw.) Wint, 1887, Pilze, p. 803. 

Endothia gyrosa Schw., Ell. and Ev.. 1892, No. Amer. Pyren., p. 552. p. p. 
Endothia virginiana P. J. and H. W. And., 1912, in Phytopathology, v. 2, 

no. 6, p. 261. 
Endothia gyrosa (Schw.) Fries, Clint., 1913, in Conn. Agr. Exp. Sta. Rpt., 

1911-12, p. 425. 
Endothia pscudoradicalis Petri, 1913, In Atti R. Accad. Lincei Rend. CI. 

Sci. Fis., Mat. e Nat., s. 5, v. 22. sem. 1, fasc. 9, p. 654. 
Endothia gijrosa (Schw.) Fckl.. Hohnel, 1913, in Sitzber. K. Akad. Wiss. 
[Vienna], Math. Naturw. Kl., Abt. 1, Bd. 122, Heft 2, p. 298. 
Type specimen. — Sowerby in Herb. Kew. on Castanea sativa, New Forest, 
England. Coll. C. Lyell, Apr. 15, 1809. 

Pycxidia. — Stromata corticular or subcorticular, truncate conical to pulvi- 
nate, usually separate and gregarious, but frequently confluent, 0.75 to 3 mm. 
in diameter by 0.5 to 2.5 mm. high, compact, varying from light auburn to 
chestnut on the surface and capucine yellow to cadmium orange within ; 
pycnidia consisting of simple or more or less complex and irregular chambers 
in the stroma, opening by an irregular pore or slit at the apex of the stroma ; 
sporophores usually simple, sometimes branched near the base, cylindric to 
subclavate, 10 to 13 n long, sometimes 24 to 30; pycnospores oblong to rod- 
like, pale yellowish in mass, 3 to 5 by 1.5 to 2 n, mostly 3.5 to 4 by 2 fi. 

Perithecia. — Stromata the same or similar to those producing pycnidia ; 
peritheeia membranous, few to many, mostly 15 to 25, 300 to 400 n in diameter, 
usually arising in the lower portion of the stroma, irregularly arranged in one 
to three layers, prolonged into slender necks which penetrate the stroma above 
and protrude usually from 300 to 600 p, terminating in conical ostioles ; asci 
oblong fusoid or subclavate, very short stipitate, 30 to 40 by 6 to S /x, mostly 
30 to 35 by 7 p, ascospores irregularly biseriate, oblong fusoid or subellipsoid, 
not constricted at the septum, hyaline with a thin gelatinous envelope, 6 to 10 
by 3 to 4.5 p, mostly 6.5 to 9 by 3 to 4 /x.. 

Cultural characters. — Cultures one month old on white corn meal show a 
compact growth with a nearly smooth surface. The color ranges from light 
cadmium to empire yellow, and the medium becomes perilla purple. Pycnidia 
and spores usually appear a little later, forming large erumpent stromata 
which extrude thick masses of pycnospores. The light mycelium with large 
43737°— Bull. 380—17 2 



18 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

pycnidial stromata and spore masses are distinguishing characters on this 
medium. 

Hosts. — America: Exposed roots and branches of Q. alba, Q. coceinca, Q. 
marylandica, (,>. prinus, Q. rubra, Q. velutina, and Castanea dentata. Europe: 
Specimens examined, Quercus pedunculata, Castanea sativa, Alnus glutinosa, 
Ulmus campestris, Carpinus betula, and Corylus sp. Japan: Castanea sp. and 
Pasania sp. It is also reported on Aesculus, Fagus, and Juglans by Traverso. 

Type locality. — New Forest, England. 

Geographical distribution. — America: Southern Pennsylvania and Ohio to 
South Carolina and northern Mississippi. Europe: Southern England, France, 
South Germany, and Switzerland to southern Italy and Transcaucasia. Asia: 
Japan. 

Illustrations.— Sowerby, 1814, Col. Fig. Engl. Fungi, Sup., pi. 438; Currey, 
1858, in Trans. Linn. Soc. London, v. 22, pt. 3, pi. 47, fig. 89 (2 upper spores) ; 
Ces. and De Not., 1863, in Comm. Soc. Crittog. Ital., pi. 3 ; Sacc, 1873, in Atti 
Spc. Veneto-Trentina Sci. Nat. Padova, v. 2, fasc. 1, pi. 14, fig. 63-65 ; Sacc, 1883, 
Gen. Pyren., pi. 6, fig. 6 ; Ruhl., 1900, in Hedwigia, Bd. 39, pi. 2, fig. 10 ; Trav., 
1906, in Soc. Bot Ital. Fl. Ital. Cript., pars 1, v. 2, fasc. 1, p. 180, fig. 34; P. J. 
and H. W. And., 1913, in Penn. Chestnut Tree Blight Com. Bui. 4, p. 22, fig. 2, 
A and C; Clint., 1913, in Conn. Agr. Exp. Sta. Rpt, 1911-12, pi. 28, fig. b, e, 
h, and j ; Petri, 1913, in Atti R. Accad. Lincei Rend. CI. Sci. Fis., Mat. e Nat, 
v. 22, sem. 1, fasc. 9, p. 656, fig. 1-3. 

Exsiccati. — Pycnidia : Thiim. Myc. Univ., 769, on Castanea ; Sacc. Myc. Yen., 
670, on Carpinus betula; Sacc. Myc. Ven., 929, on Castanea. Perithecia : Fckl. 
Fun. Nass., 640, on Ulmus campestris; Erb. Critt. Ital., 9S6, on Castanea; Rab. 
Herb. Viv. Myc, 254, on Castanea. 

Roum. Fun. Sel. Gal., 989, labeled Endothia gyrosa Schw. on beech is appar- 
ently young Hypoxylon coccineum. 

The most important synonyms given here have already been dis- 
cussed. Of the others the writers have examined the types or col- 
lections upon which the identifications w T ere based. All the material 
of Endothia in the herbaria of Cesati, De Notaris, Fuckel, and 
Berkeley, as well as other smaller collections, has been carefully 
studied. E. virginiana And. and And. has been studied in cultures, 
as well as typical specimens from the authors of the species, and 
agrees in every particular with E. fluens. 

Through the kindness of Dr. Petri a part of the type of his 
E. pseudoradicalis has been examined, but unfortunately no cultures 
could be obtained from the specimen. The writers have been unable 
to distinguish his specimen from forms of E. fluens which appear to 
show all the intermediate conditions of variation connecting it with 
typical E. fluens. The ascospores of E. fluens are more variable in 
size and shape than those of any other species of Endothia studied. 
After examining many specimens of this species from Europe, it 
does not seem possible at present to separate any of them. The case 
of E. pseudoradicalis can not perhaps be regarded as closed until 
more material of it has been collected and compared in culture. In 
fact, the slide from the type of Sphaeria radicalis Schw. shows 
ascospores of both the narrow and broad form. The photomicro- 



ENDOTHIA PARASITICA AND RELATED SPECIES. 19 

graph, Plate XVII, fig. 9, shows an ascospore which agrees with 
Petri's description and figures. 

ENDOTHIA FLUENS MISSISSIPPIENSIS S. and S. nov. comb. 

Synonym : 

Endothia radicalis mississippiensis Shear and Stevens in U. S. Uept. Agr., 
Bur. Plant Indus. Cir. 131, p. 4. 1913. 

Type specimen. — No. 1782, on Castanea dentata, Blue Mountain, Miss., N. E. 
Stevens, Feb. 13, 1913. Deposited in Pathological and Mycological Collec- 
tions, Bureau of Plant Industry. 

Cultural characters. — Cultures one month old on white corn meal show a 
compact, rather uniform surface, the color of the mycelium varying from cad- 
mium orange to xanthine orange. This variety is distinguished from the species 
by the color of its mycelium, by the numerous small pycnidia thickly scattered 
over the surface of the culture, and by the lack of any purple color in the 
medium. 

Hosts. — Castanea dentata, Quercus alba, and Q. velutina. 

Geographical distribution. — Northern Mississippi, Kentucky, Tennessee. 

Collections examined. — On Castanea dentata: No. 1706 A. pycnidia, Corinth, 
Miss., T. E. Snyder ; no. 708, pycnidia, Dumas, Miss., T. E. S. ; no. 1782, 
ascospores, Blue Mountain, Miss., N. E. S. ; no. 1806, ascospores, Blue Moun- 
tain, Miss., N. E. S. On Quercus : No. 19S9, pycnidia, Danville, Ky., N. E. S. ; 
no. 1995, pycnidia, Danville, Ky., N. E. S. ; no. 2032, pycnidia, Lexington, Tenn., 
N. E. S. ; no. 2255, pycnidia. Sardis, Miss., S. and S. 

No morphological characters have yet been found to distinguish this variety. 
It is therefore separated on its cultural characters, which are marked and 
constant. The plant was first collected by T. E. Snyder, of the Bureau of Ento- 
mology. 

ENDOTHIA LONGIROSTRIS Earle, 1900, in Muhlenbergia, v. 1, no. 1, p. 14. 

Synonym : 

Perithecia : Diatrype radical is (Schw.) Fries, Mont., 1855, in Ann. Sci. Nat. 
Bot. 4, t. 3, p. 123. Not Schw. 

Type specimen. — No. 4340. A. A. Heller, Plants of Porto Rico. In Herb. 
N. Y. Bot. C4arden. 

Pycnidia. — Stromata corticular, erumpent, gregarious, sometimes confluent, 
1 to 3 mm. in diameter, subcoriaceous, surface orange rufous to chestnut, in- 
terior zinc orange ; pycnidia consisting of irregular labyrinthiform cavities open- 
ing by a single large pore or irregular rupture at the apex of the stroma ; 
sporophores slender, somewhat tapering upward, mostly S to 10 n long ; pyeno- 
spores oblong elliptic, hyaline or yellowish in mass, when expelled forming a 
stout spore horn or tendril, colored like the stroma on the outside, 2 to 4 
by 1 to 1.5 jit. 

Perithecia. — Stromata the same as those producing pycnidia, but larger and 
frequently confluent, forming linear series in crevices in the bark ; perithecia 
arising usually at the base of the pyenidial stroma, mostly 3 to 10 in the sepa- 
rate stromata, membranous, 300 to 400 ix in diameter, mostly in a single irregu- 
lar series, prolonged into long necks, 1.5 to nearly 1 cm. long, sec. Earle, inter- 
nally black, externally same color and structure as the stroma ; ostiole acute : 
asci oblong cylindric to fusiform, 25 to 35 by 5 to 7 fi, mostly 30 by 6 /i ; asco- 
spores overlapping uniseriate to irregularly biseriate, hyaline, ovoid to ovoid 
elliptical, 6 to 8.5 by 3 to 4 ft, mostly 7 to 7.5 by 3 to 3.5 fi. 



20 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

Cultubal chabacteks. — Cultures one month old on white corn meal have a 
uniform cadmium orange to xanthine orange color. The entire surface is covered 
uiili a compact growth, irregularly ridged. Tiny mars orange spore masses are 
scattered irregularly over the surface. Cultures of this species closely' resemble 
/•:. fluens mississippiehsis on this medium, being distinguished by the smaller and 
much less numerous spore masses. The medium is changed to amber brown 
just below the mycelium, shading into mars yellow; whereas, in the case of 
/;. fluens mississippiensis the color of the medium is very little changed. 

Type locality. — " Calcareous hills east of Santurce, Porto Rico, altitude 
10 ft." 

Geographical distribution. — Porto Rico and French Guiana. 

Exsiccati. — Pycnidia and perithecia : Heller, Plants of Porto Rico, no. 4340. 

This species, which appears to be subtropical or tropical in its 
range, is known at present from only three collections, the type col- 
lection from Porto Rico, a collection by Prof. N. Wille, No. 816, 
Porto Eico, distributed by the New York Botanical Garden, from 
which the cultures were obtained ; and one made by Leprieur, No. 392, 
in French Guiana, and determined by Montagne as Diatrype radicalis 
(Schw.). A specimen of this collection apparently labeled by Mon- 
tagne and preserved in the Delessert Herbarium at Geneva has been 
examined and found to agree with the type material of E. longiros- 
tris. It is readily distinguished from E. tropicaUs by its smaller asco- 
spores and pycnospores, and from E. fluens by its narrower and 
more acute ascospores and the long, slender necks of the perithecia. 

ENDOTHIA TROPICALIS Shear and Stevens sp. nov. 

Synonyms : 

Diatrype gyrosa Berk, and Broome, 1875, in Jour. Linn. Soc. [London], 

v. 14. p. 124. 
Nectria gyrosa Berk, and Broome, 1877, in Jour. Linn. Soc. [London], 

v. 15, p. 86. 
Cryphonectria gyrosa (Berk, and Broome) Sacc, in Syll. Fung., v. 17, 

p. 784. 1905. 
Endothia gyrosa (Schw.) Fckl., Hohnel, 1909, in Sitzber. K. Akad. Wiss. 
[Vienna], Math. Naturw. Kl., Abt. 1, Bel. 118, Heft 9, p. 1480. 
Type specimen. — No. 2807 S. and S., on Elacocarijus glandulifer, Hakgala, 
Ceylon, Coll. T. Peteh, August, 1913. 

Pycnidia. — Stromata corticular, pustular to pulvinate, usually gregarious or 
scattered, rarely confluent, 1 to 5 mm. in diameter, early becoming friable, 
orange chrome when fresh to sanford brown when old and weathered ; pycnidia 
consisting of numerous irregular cavities in the stroma; sporophores mostly 
simple, clavate, tapering above. G to 10 n long.; pycnospores continuous, oblong 
in cylindric, very variable in size and shape, pale yellowish in mass, 3.5 to 
7 by 1.5 to 2.5 n. 

Perithecia. — Stromata the same or similar to those bearing pycnidia ; peri- 
thecia black, membranous, collapsing when dry, 5 to 50 or more in a stroma; 
250 t<> 500 ix diameter, irregularly arranged in one to three layers, bearing 
slender necks which penetrate the stroma and project 0.25 to 1 mm., termi- 
nating in acute ostioles ; asci oblong or subclavate, nearly sessile, 40 to 50 by 
7 fi ; ascospores irregularly biseriate, subelliptical, obtuse, not constricted at 



ENDOTHIA PARASITICA AND RELATED SPECIES. 21 

the septum, hyaline with a gelatinous envelope, 7.5 to 10.5 by 3.5 to 5 fx, mostly 
8 to 10 by 4 to 4.5 ft. 

Cultural characters. — Cultures one month old on white corn meal show 
small numerous, thickly scattered pycnidia and spore masses very similar to E. 
parasitica. The mycelium is orange buff to apricot orange. Tins species differs 
from E. parasitica in culture, chiefly in the brighter color of its mycelium. 

Host. — Rotten logs and stumps of Elaeocarpus glandulifer. 

Type locality. — Hakgala, Ceylon. 

Geographical distribution. — Only known from Ceylon at present. One 
other collection of this species, No. 290 G. H. K. T. [Thwaite], N. Eliya, 
Ceylon, 6,000 feet, has been examined in the Kew Herbarium. 

Through the kindness of Mr. T. Fetch, of Peredeniya, the writers 
have received two large collections of this fungus. Some of the 
material was in a living condition and enabled the writers to obtain 
pure cultures for comparison with the other species of Endothia. 
This species is closely related to E. parasitica, but is readily sepa- 
rated by its larger ascospores and larger and more variable pycno- 
spores and its nonparasitic habit. 

ENDOTHIA PARASITICA (Murr.) P. J. and H. W. And., 1912, in Phytopathology, v. 2, no. 6, p. 262 

Synonyms : 

Diaporthe parasitica Murrill, 1906, in Torreya, v. 6, no. 9, p. 1S9. 

Valsoncctria parasitica Rehm, 1907, Asc. Exs., no. 1710. 

Valsonectria parasitica Rehm, 1907, in Ann. Mycol., v. 5, no. 3, p. 210. 

Endothia gyrosa var. parasitica Clint. 1912, in Science, n. s., v. 36, no. 939, 
p. 913. 

Endothia gyrosa (Schw.) Fckl. Hohnel, 1909, in Sitzber. K. Akad. Wiss. 
[Vienna], Math. Naturw. Kl.. Abt. 1, Bd. IIS, Heft 9, p. 1480. 
Type specimen. — Herbarium N. Y. Bot. Garden, on Castanca dentata, Bronx 
Park, New York City, Nov. 26, 1905, Coll. W. A. Murrill. 

Pycnidia. — Stromata corticular, slightly erumpent to truncate conical, usually 
separate and gregarious, frequently confluent in more or less linear series 
especially in old rimose bark, 0.75 to 3 mm. in diameter by 0.5 to 2.5 mm. 
high, varying from capucine yellow when young to auburn when old and 
weathered ; pycnidia consisting of irregular cavities in the stroma, 100 to 300 
,tt in diameter ; sporophores mostly simple, subclavate, acute at the apex, usually 
12 to 20 by 1.5 /x, more elongated filaments sometimes reaching 50 fi or more 
being frequently found among the normal sporophores ; pycnospores, oblong to 
<?ylindric, rounded at the ends, 3 to 5 by 1.5 to 2, mostly 3.5 to 4.5 by 1.5 to 
2 ix, pale yellowish in mass under the microscope; old spore tendrils coral red. 

Perithecia. — Stromata the same or similar to the pycnidial stromata; peri- 
thecia dark, membranous, globose to flask shaped, collapsing when dry, 5 to 50 
or sometimes more in a stroma, 300 to 400 fx in diameter, irregularly arranged 
in one to three layers and bearing slender necks projecting above the stroma, 
300 to 600 ix, colored like the stroma on the outside and terminating in acute 
ostioles; asci oblong elliptical to subclavate, nearly sessile, 30 to 60 by 7 to 9 p, 
mostly 40 to 50 by S fi ; ascospores irregularly biseriate, ellipsoid, obtuse, some- 
times constricted at the septum, hyaline, with a gelatinous envelope, 7 to 11 
by 3.5 to 5 fi, mostly 8 to 9 by 4 to 4.5 /x. 

Cultural characters. — Cultures one month old on white corn meal have a 
white to pale orange yellow surface mycelium and produce numerous minute 



22 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

pycnidia and pale yellow spore masses. It is distinguished from its nearest 
relative, E. tropicalis, by t lie lighter color of the mycelium. 

Hosts.- Castanea dentata, C. sativa and cult, vars., C. pumila, Castanea mol- 
lissima from China and Castanea japonica from Japan, Quercus alba, Q. prinns, 
q. velutina, Acer sp. 

It; is also reported on Rhus typhma and Carya ovata by Anderson and 
Rankin. 

Type locality. — Bronx Park, New York City. 

Geographical distribution. — Southern Maine to Ohio and southward to 
North Carolina; also Missouri, Iowa, Nebraska, British Columbia, China, 
and Japan. 

Illustrations. — Murrill, 1908, in Torreya, v. S, no. 5, p. Ill, fig. 2; Petri, 
L913, in Atti R. Accad. Lincei, Rend. CI. Sci. Fis., Mat. e Nat, s. 5, v. 22; sem. 1, 
Ease. 1). p. »;•".('». fig. 4; Heald, 1913, in Penn. Chestnut Tree Blight Com. Bui. 5, 
pi. 13; Clint. 1913, in Conn. Agr. Exp. Sta. Rpt, 1911/12, pi. 28, fig. c, f, i, 
and k; P. J. and H. W. And., 1913, in Penn. Chestnut Tree Blight Com. Bui. 
i, p. 22, fig. 2, B and D; P. J. And. and Rank., 1914, in N. Y. Cornell Agr. 
Exp. Sta. Bui. 347, p. 562, fig. 89. 

Exsiccati. — Pycnidia and perithecia : Rehm, Asa, 1710; Wilson and Seaver, 
Asc and Low. Fun., 3; Bart. Fun. Col., 2926; all on Castanea dentata. 

This species is closely related in its morphological characters to 
all the species of section 2 of the genus. It is most likely to be 
confused with E.fluens, but shows constant differences, though slight, 
in size and shape of ascospores. They are predominantly broader 
and more uniform in shape, as shown by the table of measurements 
on page 35. In its active parasitic condition on Castanea it can 
always be distinguished by the presence of the mycelial " fans " 
in the inner bark, as shown in Plate VIII. It has been confused 
with E. gyrosa through an erroneous identification of that species. 

MORPHOLOGY AND DEVELOPMENT. 

MYCELIUM. 

By far the most striking mycelial character is the production by 
E. parasitica of yellow or buff fan-shaped formations of mycelium 
in the cambium and bark of the host. These "fans" vary from 1 
mm. to 1 cm. or more in width, and are composed of radiating 
hyphse closely pressed together to form a continuous layer. (PI. 
VIII.) So constant are these mycelial fans in their occurrence and 
so characteristic in their appearance that they furnish the most re- 
liable field character for distinguishing E. parasitica from related 
species and may quite properly be regarded as a specific character 
when the fungus is growing in living trees. 

Anderson and Anderson (2, p. 204) first called attention to the 
fact that these fan-shaped formations of mycelium are absent from 
E. fluens. Rankin (62, p. 248) states that when the fungus grows 
saprophytically or while the tree is dormant these fans are not pro- 
duced. Anderson and Rankin (6, p. 565) report that in inoculations 



ENDOTHIA PARASITICA AND RELATED SPECIES. 23 

on Quercus alba and Q. prinus, E. parasitica produced the typical 
mycelial fans. 

Anderson (1, p. 14) considers that the occurrence of these fans 
is associated with the parasitic habit of the fungus. In his opinion 
single hyphse do not possess the power of penetrating the living cells, 
but the fungus grows on the injured and dead cells about a wound 
until a quantity of mycelium is accumulated, when it " en masse 
pushes through the living tissues of the bark." This view is also 
held by Keefer (45, p. 193), who adds that "the action of the ad- 
vancing mycelial mats seems to be physical rather than chemical, 
and the cells are mechanically broken to pieces." 

Rankin, however, states (62, p. 248) that "The host cells, just 
in advance of the edges of the fan, are disintegrated and form a 
distinct gelatinous band, which can be seen with the naked eye." 
This observation suggests to the writers that some toxic or enzymatic 
action upon the cells of the host probably occurs before the cells 
are actually invaded by the fungus hyphse. Careful investigation 
of this point should go far toward determining the causes of the 
parasitism of this fungus. Whatever the cause or function of these 
fans, they are very characteristic, and the writers have found them 
invariably in diseased material of Castanea in America, as well as 
in that from China and in two specimens of E. parasitica on Quercus. 

A similar mycelial formation, fanlike in form, 1 is produced by 
Armillaria mellea in the bark of roots attacked by this fungus. Ex- 
cellent specimens of the Armillaria mycelial fans have been pre- 
sented to the writers by Prof. Wm. T. Home, of the University of 
California. 

STROMATA. 

Under the name Melogramma gyrosum, in which they included 
specimens of both Endothia gyrosa and E. fluem, the Tulasnes (83, 
pp. 87-89) described the structure of Endothia in some detail. Their 
description was based chiefly on abundant local material of E. fluens 
collected on Carpinus betulus L. during several years, but they also 
used material sent by Guepin from western France, pycnidial ma- 
terial on chestnut from Italy, American material sent by Schweinitz 
to Brongniart and preserved in the Paris Museum, and specimens 
from Carolina sent by Berkeley. According to the Tulasnes (83, 
p. 87 ) 2 the stromata are "developed singly and emerge gradually 
as so many scattered points with fibers radiating in all directions, 
soon swell into a yellowish cone, rupture the epidermis above them, 

1 Since this manuscript was completed a very similar mycelial formation has come to 
the writers' attention. As figured by Nowell (50), pi. 1, Rosellinia pepo, when growing 
under the bark of lime trees, forms mycelial fans resembling those of Endothia parasitica. 

2 The portions in quotations are rather free translations of the authors' Latin. 



24 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

and put forth a very blunt apex. All are composed of a corky, 
parenchymatous, very dense, soft yellow material. The mature 
ones attain a diameter of 3 to 4 millimeters and a height of 1 to 2 
millimeters, and on the somewhat reddish, and finally rusty red to 
yellow top, they are marked by black points, the ostioles." The 
Tulasnes observed that before the stromata reached their full size 
the pycnidial cavities were formed within them, sometimes " widely 
open," sometimes "narrow labyrinthine," and that through one or 
many openings in the top of the pycnidia, the long, twisted, orange 
tendrils, composed of mucus, and innumerable thin linear spores 
were expelled. " Perithecia are developed chiefly in stromata des- 
titute of spermogonia, or more often with only a few * * * they 
arise very abundantly and irregularly, some barely buried in the 
yellow corklike substance, others lower down and seemingly located 
in the bark of the host itself." 

Although the Tulasnes included all their material under a single 
species, they noted that the pycnidial stromata of the American 
specimens (really Endothia gyrosa) differed considerably from the 
European (E. fluens). In describing the former, they say (83, p. 
88) "The American fungus is said to grow in the bark of Fagus 
and Juglans * * * as a whole it abounds with numerous, very 
small spermatia. Wherefore if it is very thinly sectioned, the pieces, 
examined with a compound microscope, show cavities just as if you 
had before your eyes the smallest Gautieria or Balsamia." The 
Tulasnes do not try to distinguish definitely between stroma and 
nrycelium, but merely state that the stromata develop within the 
mycelium. 

Ruhland (67), who was the next writer to discuss the morphology 
of a species of Endothia, defines the various portions of the fungus 
body in detail. According to his definition (p. 16) a "stroma (in 
distinction from mycelium) is the sum total of that part of the 
vegetative portion of the fungus body, which, without serving ex- 
clusively for absorption, takes part in the formation of the fruit 
body." He sets aside Fuisting's (36, p. 185) division of the fungus 
body into an epistroma and a hypostroma, as essentially nothing but 
the distinction of " conidial layers " and " perithecial stroma." 

Ruhland divides the fungus body into an ectostroma and an ento- 
stroma. The ectostroma grows " on the upper surface of the paren- 
chyma of the bark, between it and the periderm, and is composed of 
v generally wide-lumened plectenchyma which does not possess the 
power of absorption." This portion has the following functions: 
" The formation of the conidia, the opening and breaking off of the 
periderm, and the stimulation of the development of the entostroma." 
The entostroma, on the other hand, according to Ruhland, " lives in 
the parenchyma of the bark, and while young is in a high degree 



Bui. 380, U. S. Dept. of Agriculture. 



Plate IX. 




~\ 



& 



1 




It*. - 










mm 



ENDOTHIA 



GYROSA. 



VERTICAL SECTIONS 
BEECH. X32. 



OF STROMATA ON 



Fiq. 1.— Showing Numerous Pycnidial Cavities andTwo Mature Perithecia. 
Fig. 2.— Showing Mature Pycnidia and Perithecia Side by Side. 

Except where otherwise indicated, the photomicrographs of stromata are from unstained 
sections cut with a freezing microtome. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XII. 




ENDOTHIA PARASITICA AND RELATED SPECIES. 25 

capable of absorption, a power which it retains relatively perma- 
nently.''' In addition to its absorptive function the entostroma forms 
the pseudoparenchymatic cover for the perithecial walls. 

Euhland studied herbarium material from the Eoyal Botanic Mu- 
seum of Berlin and specimens from Saccardo and Cesati, and de- 
scribed it under the name of Endothia rad'walis (Schw.) Fr. (E. 
fiuens of the present writers). He distinguishes an ectostroma, 
shaped like a truncated cone, consisting of fine, thin-walled hyphee, 
so closely interwoven that the whole structure has a comparatively 
firm quality. Among these hyphse are crystals of calcium oxalate. 
As soon as this ectostroma breaks through the bark there is formed 
near the middle a short-lived 1-chambered pycnidium. Below this 
ectostroma (height 0.5 to 0.6 mm., diameter 0.7 to 1 mm.) the ento- 
stroma grows out as a mycelium through the upper portion of the 
bark. Euhland says, " The entostroma with us does not produce per- 
ithecia, but remains wholly mycelial." He studied the perithecial 
stage in Cesati's specimens, however, and concludes that the peri- 
thecia originate without much change in the size of the entostroma 
and at a considerable distance, about 1 mm., below the ectostroma. 
The long necks then penetrate through the overlying entostroma 
and into the ectostroma to the base of the now functionless pycnidia. 
The upper portion of the ectostroma is then quickly killed and 
thrown off. 

Pantanelli briefly described the stromata of the genus Endothia, 
and pointed out several morphological characters which he considers 
distinctive of E. parasitica in contrast to E. fiuens. Aside from spore 
characters, which will be discussed later, Pantanelli (60, p. 870) con- 
siders that E. parasitica is characterized by numerous stromata, at 
first embedded in the bark, finally free; by pycnidial cavities numer- 
ous and irregularly arranged in various planes in the stromata deep 
in the bark; pycnidial stromata 1.1 to 1.2 mm. in height and 2.1 to 2.2 
mm. in diameter; ascogenous stromata, height 1.8 to 2 mm., length 
2.5 to 3.4; width, 3 to 3.2 mm.; perithecia arranged in two or three 
layers; necks of perithecia averaging 1.25 mm., with inconspicuous 
ostioles ; walls of the perithecia uncolored or light brown. 

Endothia fiuens, on the other hand, has isolated stromata, chiefly 
outside the bark; pycnidia aggregated, regularly arranged in a single 
superficial series; pycnidial stromata, height 0.1 to 0.5 mm., diameter 
1.1 to 1.3 mm. ; ascogenous stromata, height 1.1 to 1.4 mm., length 
2.5 to 3.2 mm., width 1.2 mm. ; perithecia arranged in a single row ; 
necks of perithecia averaging 0.45 mm.; ostioles prominent; walls 
of the perithecia black. 

Anderson (1, pp. 17-24) described the development of the fructifi- 
cations of Endothia parasitica in detail. He studied the growth of 



26 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

the pycnidia in pure culture and made sections of perithecial stro- 
mata growing on bark. 

According to Anderson, the pycnidium originates as a mass of 
densely intertwined hypha?, in the center of which numerous pycno- 
spores are cut off. The crowding of these spores increases the size 
of the pycnidial cavity and crowds the outer hypha? together to form 
a sort of wall. The ostiole is formed in the top by the loosening of 
the hyphae. The stroma always starts as a loose growth of hyphse 
around the pj^cnidium. It does not precede, but follows the first 
stages in the development of that organ. A fluffy growth of light- 
yellow mycelium surrounds the pycnidium and covers it over. If 
these are embedded and sectioned, they will be found to contain a 
loose tangle of undifferentiated hyphas surrounding a central pyc- 
nidium. But as soon as the cork layer is broken the stroma under- 
goes a change. There is a rapid increase in size and at the same time 
a differentiation of the cells at the tips of those branches which 
reach the exposed surface. These cells now become shorter and 
thicker, acquire heavier walls, and are densely crowded together, so 
that in cross section they appear as a pseudoparenchymatous tissue. 
The layer thus formed covers all the exposed surface of the stroma 
and also grows up around the necks of the perithecia. The stroma 
increases very rapidly in size and a mass of stromatic tissue is 
formed beneath the pycnidia, which are thus pushed out through 
the cork layer into the periphery. The primordia of the perithecia 
are formed usually in the tissues of the bark below the base of the 
original pycnidium, but at times are formed well up in the stroma. 
Usually 15 to 30 perithecia mature in a stroma. 

According to the writers' observations, the Tulasnes' description 
(83, pp. 87-89) is substantially correct so far as it goes. They, of 
course, placed pycnidial material of Endothia gyrosa in the same 
species with E. fluens, but, as already noted, they observed the dif- 
ference in the structure of the stromata and aptly compared the 
pycnidial stroma of E. gyrosa, as seen in section, to a Gautieria. 

The division of the stroma into ectostroma and entostroma made 
by Ruhland (67, p. 16) has, at least in the species of Endothia, 
no validity whatever. While it is true that pycnidia usually occur 
in the portion of the stroma first developed and perithecia often 
develop below them, this is by no means an invariable rule; and 
while stromata are developed which contain only pycnidia, other 
stromata apparently produce only perithecia or no spores whatever. 
Certainly no portion of the stroma can be distinguished which in- 
variably produces only perithecia or only pycnidia, On the con- 
trary, there is great variation in the relative position and time of 
appearance of the two types of fruiting structures. Also, while 



ENDOTHIA PARASITICA AND RELATED SPECIES. 27 

the pycnidial cavity is sometimes small and simple, as described by 
Ruhland, it is more often large and much convoluted. (See Pis. 
XV and XVI.) 

While the writers, of course, agree with Pantanelli (60) that 
Endothia parasitica and E. puens are distinct species, many of the 
stromatic characters which he describes are so variable as to be 
unreliable. In an examination of a large number of specimens the 
writers have been unable to find any constant difference in the ar- 
rangement or structure of the pycnidial stromata. This seems to 
depend chiefly in both species on the character of the bark and the 
moisture conditions. As to size, while the stromata of E. parasitica 
examined average somewhat larger than those of E. fiuens, the range 
of the pycnidial stromata is about the same in the two species, vary- 
ing from 0.4 to 2 mm. in height and from 0.2 to 3 mm. in length. 

The ascogenous stromata are also very variable in size. Those 
measured by the writers varied in height from 0.5 to 2 mm. in En- 
dothia parasitica and from 0.5 to 2.3 mm. in E. fluens. In width the 
perithecial stromata were from 1 to 2.5 mm. in both species, while 
there is apparently no method for determining their length, since on 
thick-barked trees continuous narrow masses of perithecial stromata 
are often formed in the crevices of the bark. These stromatal masses 
frequently extend from 5 to 10 cm., and while they are in all prob- 
ability formed by the fusion of several stromata there is no way of 
determining how far each extends. 

The arrangement of the perithecia mentioned by Pantanelli (60) 
as a specific character seems to depend on the nature of the bark of 
the host. When the bark is thin and easily ruptured the stromata 
tend to spread out so that the perithecia occur in a single layer, 
while if the bark is thick and deeply ridged the stromata are thicker 
and the perithecia occur in two or more layers. That this is not a 
specific character is clearly shown by Plate XVI. Figures 1 and 3 
of this plate show a stroma of E. parasitica and of E. fluens, respec- 
tively, both with three layers of perithecia, while Plate XVI, figure 2, 
and Plate X, figure 1. show stromata of both species with perithecia 
arranged in a single layer. 

Although, as already indicated, the stromata of each species are 
very variable, they are sufficiently distinct so that the native American 
species may readily be distinguished in the field. 

The stromatic characters of Endothia gyrosa and E. singularis 
are much more distinct than those of the other species. The stromata 
of E. gyrosa. are erumpent, irregularly subglobose, with a rather 
roughened surface. They are usually from 1.5 to 2 mm. in height 
and vary from 1.5 to 3 mm. in width. The stromata of E. singularis 
are much larger than those of any other species of Endothia, being 



28 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

usually from 2 to 4 mm. in length and 3 to 5 mm. or more in diameter. 
They are decidedly erumpent, rather regular, and subglobose in out- 
line. The contents of the stromata are brick red in color and are very 
powdery when old. 

The stromata of EndotMa fluens, E. ftuens rrdssissippiensis, and 
E. parasUica resemble each other so closely that the species are prac- 
tically indistinguishable on this basis. All these species are char- 
acterized by partially embedded, confluent stromata which vary 
greatly in outline, depending on the nature of the bark of the host. 
As already stated, they vary from 0.4 to 2 mm. in height and from 
0.7 to 5 mm. or more in length where confluent. E. tropicalis and 
E. longirostris resemble this group in their stromatic characters. 

Pycnidia, — The pycnidia of EndotMa gyrosa and E. singularis are 
very distinctive also. The pycnidial cavities of E. gyrosa are narrow 
and so irregularly convoluted that in a section of the stroma the 
cavities vary in width from 0.03 to 0.3 mm., averaging about 0.15 
mm. On the whole, however, they are much narrower than those 
of E. fluens or E. parasitica. A section of a pycnidial stroma of E. 
gyrosa shows numerous irregular, rounded to elongate chambers 
separated by narrow walls. The pycnidial cavities of E. singularis 
(PL XIII) are minute, 0.03 mm. in diameter, nearly spherical, 
evenly distributed through the stroma and separated at first by com- 
paratively thick walls, which disintegrate and become powdery when 
the stroma is old. 

So far as the writers have been able to determine, the " tendrils " 
of pycnospores so characteristic of EndotMa fluens and E. parasitica 
are not formed in either E. gyrosa or E. singularis. Mature pycnidial 
stromata of E. gyrosa w T hen placed in a moist chamber exude nu- 
merous droplets containing spores and scattered well over the surface 
of the stromata. The writers have been unable to produce any such 
change by placing the pycnidial stromata of E. singularis in moist 
chambers, and it seems probable that the pycnospores of E. singularis 
are set free by the breaking down of the outer walls of the stromata. 
As already mentioned, the inner partitions are friable, so the spores 
are readily scattered by the wind. 

The pycnidial cavities of EndotMa fluens and E. parasitica, and 
apparently all the other species of this section of the genus, vary 
from 0.2 to 0.3 mm. or more in diameter and may consist of a 
single chamber rather regular in outline (PI. XIV, fig. 1) or of an 
irregular cavity consisting of many chambers (PI. XV, fig. 3) more 
or less complete^ separated from one another. These species differ 
from E. gyrosa in that the pycnospores are usually discharged through 
a single opening near the top of the stroma and emerge in a single 
twisted tendril. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 29 

Development of the stromata. — The writers have not followed the 
development of the stromata in culture, but an examination of nu- 
merous sections of Endothia singularis, E.gyrosa, E. fluens, and E. 
parasitica and a study of the three latter species under field condi- 
tions on various hosts shows that their development is by no means 
as uniform as indicated in Anderson's description (1). 

According to Anderson, the pycnidium develops first, and about 
the young pycnidium the stroma is quickly formed, while the 
perithecia arise later, usually in the lower portion of the stroma. 
This may perhaps be considered the typical course of development, 
and pycnidia are often found above the perithecia, but all variations 
occur. A large stroma may be developed without a sign of a pyc- 
nidium (PI. XV, fig. 2). In some cases there is a considerable por- 
tion of the stroma above the pycnidial cavity (PI. XIV, fig. 2). or 
the pycnidial cavities may be surrounded by a thick stroma (PL 
XIV, fig. L, and PL XV, fig. 1). Sometimes, on the other hand, 
they are large and irregular, with little stroma (PL XV, fig. 3). 

The perithecia by no means uniformly arise below the pycnidia, 
but the two often occur side by side in the same stroma (PL IX, 
fig. 2; PL XIV, fig. 3; and PL XII). Sometimes, even, the 
perithecia are above the pycnidia (PL XIV, fig. 2). There seems 
to be no constant relation either as to the relative number of pyc- 
nidia or of perithecia in a single stroma. Sometimes the pycnidial 
portion is much larger (PL IX, fig. 1) : sometimes the perithecia 
predominate (PL X, fig. 2) ; and sometimes the two portions are 
practically equal (PL XII). 

A like variability apparently occurs in the sequence of the fruit- 
ing bodies. As the figures show, the pycnidia sometimes develop 
after the perithecia; the reverse order is frequent; while in several 
sections (PL XII, and PL XIV, fig. 3) the two types of fruiting 
bodies were side by side and were producing mature spores abun- 
dantly at the same time. Just what factors determine the produc- 
tion of each type of spore or prevent or delay spore production is 
unknown. It seems probable, however, that climatic influences may 
prevent the development of ascospores in many cases. The action 
of climate may be very indirect, however, for no ascospores of any 
species have yet been obtained in artificial cultures, though En- 
dothia fluens, E. fluens misslssip piensis, E. tropicalis, and E. para- 
sitica produce pycnospores abundantly on a variety of media. Cer- 
tainly, climatic factors would not account satisfactorily for the fact 
that pycnidia and perithecia are produced at the same time in ad- 
jacent stromata, or even in different parts of the same stroma. 

The size of the perithecia is rather uniform in the various species 
(PL X, fig. 3, and Pis. XI and XVI), being about 0.35 mm. in diame- 
ter. They are typically globose to pyriform, but are usually more or 



30 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

less irregular on account of crowding. This pressure may be so 
great as to produce almost any shape, and such perithecia some- 
times measure 0.5 mm. in the greatest diameter and 0.1 mm. in the 
shortest. 

SPORE MEASUREMENTS. 

The spore measurements recorded here were made by Miss Tiller. 
In the case of dried specimens, the spores were first soaked for three 
hours in lukewarm water and then mounted in the potassium- 
glycerine-copper medium, prepared according to the following 
formula : 

1 part 2 per cent potassium acetate in water. 

1 part 40 per cent glycerine in alcohol. 

Copper acetate sufficient to color. 

In the case of fresh specimens they were mounted directly in the 
same medium. The measurements were made with a Zeiss filar 
eyepiece micrometer and a Zeiss 3 mm. 1.40 X. Ap. oil-immersion 
objective. Only approximate accuracy is claimed for these results, 
on account of the difficulty of overcoming the motion of the spores 
in a fluid medium. The results are, however, believed to be fairly 
comparable, as practically all were measured under the same condi- 
tions and treatment, and the margin of error is presumably rather 
uniform. The differences in size of pyenospores do not appear to 
be sufficient, however, to furnish diagnostic character for most of 
the species. 

The number of measurements of ascospores of Endothia fluens and 
E. parasitica is much larger than of the other species, as special 
attention was first given to these two species on account of their great 
similarity. In order to make the measurements of these species 
comparable to the others, the total number of spores of each length 
has been calculated in the percentage of the total number of spores 
measured. 

METHOD OF TABULATION. 

For better comparison, the spore measurements have been tabu- 
lated by half microns, all the spores in each specimen coming within 
0.2 of a micron of each unit or half being grouped together; e. g., 
all the spores having a length of 7.3, 7.4, 7.5, 7.6, and 7.7 microns 
are included under the heading 7.5. The tables thus show at a 
glance the number of spores of a giveh length per specimen. The 
widths have been tabulated in the same way. 

For a better comparison of the shapes of the ascospores of 
Endothia parasitica and E. fluens, the relative ratios of length to 
width in each spore have been calculated, the width being considered 
unity. The ratios of length to width were then tabulated by tenths; 
that is, all the spores in each specimen having a ratio of length to 



ENDOTIIIA PARASITICA AND RELATED SPECIES. 



31 



width from 1.76 to 1.85 microns are included under 1.8. The rela- 
tive shapes of the spores in each specimen are thus clearly shown. 

Table I. — Measurements of pyenospores and asci of Endothia. 

Pycnospore Measurements. 





Number per specimen having the given length or width. 




Specimens. 


Lengths (microns). 


Widths (mi- 
crons). 


Total. 




2 


2.5 


3 


3.5 


4 


4.5 


5 5.5 


6 


6.5 


7 


1 


1.5 


2 


2.5 




Sphaeria gyrosa Schw. , Herb. 


2 


3 


6 
5 

10 
4 


11 
9 

11 
6 

8 

6 
3 

5 
4 

2 
6 


4 
3 

3 

4 

11 

12 
5 

8 

1 

5 

11 












9 
5 

5 


15 
11 

18 
5 

8 

6 
8 

8 
3 
12 


2 
1 

1 
9 
17 

19 

4 

9 






S. gyrosa Schw. , Herb. Schwaeg. 
Endothia gyrosa on beech, Al- 




























24 
14 
25 

25 
























6 

5 
2 

1 












E. fluens on chestnut, Fort 






1 
1 

2 
4 


1 
















1 










E. fluens mississippiensis, No. 
1706A 
















16 




2 


3 










6 


14 




6 

6 


3 I 3 

1 J 


2 




4 


19 
13 


3 








1 


25 



















Lengths of Asci (Microns). 



Specimens. 


No. 


Number per specimen having the given length. 




25 


30 


35 


40 


45 50 


55 


60 


Total. 


Endothia fluens on Castanea 


1702 
1737 
1741 
1729 
1715 
1656 
1711 
1927 

1S06 


2 

2 
2 


8 
1 
5 
4 
7 
6 
16 
10 

5 
1 


11 
14 

6 
16 
16 
16 

7 
12 

14 

5 


1 

11 










22 


Do 












Do 












Do 


6 
3 
1 










26 


E. fluens on dead Castanea 










E. fluens on Castanea, Stresa, Italy 


1 


1 






25 


E. fluens on Quercus 






25 


Do 












E. fluens mississippiensis, Blue Moun- 
tain, Miss 


3 

1 

10 

2 












E. parasitica on Castanea 


1710 


2 
10 
14 










Do 


1739 
2151 




1 
4 






26 








4 


3 


27 

8 


E . gyrosa on Quercus 


1709 


1 
19 

4 
6 
6 


7 

6 

15 

13 

10 




E. gyrosa on Liquidambar 














25 


E. singularis, Palmer Lake, Colo 




5 
3 
1 












24 


E. longirostns, Porto Rico 




3 










25 


E. longirostris, French Guiana 














E. tropicalis 






6 


5 


3 


2 


16 















Widths of Asci (Microns). 



Specimens. 


Number per specimen having the given width. 




4 


5 


6 


7 


8 


9 


10 


Total. 


Endothia gyrosa 






8 
2 
2 
1 
2 
7 
3 


2 










E. singularis 


1 


8 










E. fluens, Europe 


6 
6 
6 

2 
3 
2 
1 


4 
4 
2 








E. fluens, America 












E. fluens mississippiensis 












E . longirostris, Porto Rico 




2 








E. longirostris, French Guiana 




3 
6 

7 
6 








E. tropicalis 






2 

2 
4 




10 
10 


E. parasitica, China 








E. parasitica, America 





















32 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

PYCNOSPORES. 

The pycnospores of all the species are oblong elliptic to cylindric 
in shape and so small as to make accurate measurement very difficult. 
Slight but apparently constant differences in their size in certain 
groups of species may, however, be traced. These differences are 
clearly shown in Table I. 

Endothia gyrosa, E. singidaris, and E. longirostris have smaller 
pycnospores than the other species, the most frequent lengths being 
3 and 3.5 \i.. The pycnospores of E. singularis are slightly broader 
than those of E. gyrosa and E. longirostris, being 1.5 to 2 \h, as 
against 1 to 1.5 \l in the last two species. 

Endothia fluens, E. fluens nilssissippiensis, and E. parasitica are 
even more closely similar in the size of their pycnospores than in that 
of their ascospores, the most frequent size being 4 by 2 f*. The 
pycnospores of E. tropicalis are much larger and more variable in 
size and shape than those of other species. They range from 3.5 
to 7 fJi. in length and from 1.5 to 2.5 [jl in width. 

ASCI. 

The writers have not attempted a study of the origin and early 
development of perithecia or asci in any of the species of Endothia. 
Work on this subject has been published by Anderson and Rankin 
(6), for Endothia parasitica, but the nuclear phenomena and origin 
and development of the ascogenous hyphae are not yet entirely clear. 
The part termed a trichogyne by these authors seems more likely to 
be the initial stage in the development of the neck of the perithecium 
than the relic of an organ of fertilization. 

The asci appear almost or quite sessile in most species, and 
though varying considerably in size and shape, as indicated in Table 
I, are usually oblong elliptic or subclavate, having a sort of inner 
membrane inclosing the ascospores and some thin granular matter 
extending to the apex of the ascus, where a slight thickening appears, 
as described and illustrated by Anderson for Endothia parasitica. 
A similar condition is found in various species of Pyrenomycetes and 
probably functions in some way in connection with the discharge of 
the ascospores. The asci are generally wider and slightly longer in 
E. parasitica than in E. fluens and other members of section 2. The 
asci of E. gyrosa are shorter than those of any other species. E. 
tropicalis has the longest asci. The asci of none of the species show 
a very wide range of variation, as Table I also indicates. 

PARAPHYSES. 

Most students of Endothia have reported paraphyses wanting in 
this genus. Anderson (1, p. 33, fig. 32) and Anderson and Rankin 
(6, p. 579, fig. 83) report paraphyses present and figure what they 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XII I. 




Endothia sinqularis. Ve 



rtical Section of the Major Part of a Pycn 
Stroma. X 32. 

Paraffin section stained with Bismarck brown. 



IDIAL 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XVI 








Ms 



Ai* 




ENDOTHIA PARASITICA AND E. FLUENS. VERTICAL SECTIONS OF 
STROMATA. X 20. 

Fig. 1.— E. parasitica. Showing Perithecia Arranged in Several Irregular 
Layers. Fig. 2.— E. parasitica, Showing Perithecia Arranged in a Single 
Layer. Fig. 3.— E. fluens, from Italy, Showing Perithecia Arranged in 
Several Layers. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 33 

regard as an early stage of their development. They describe them 
as branching frequently and very crooked, extending around the 
perithecium as well as upward. The writers have searched in all the 
species studied for evidence of the presence of paraphyses, but have 
never seen anything resembling paraphyses as they occur in closely 
related Pyrenomycetes. If they occur, they would seem to be of an 
unusual character and difficult to recognize or else are evanescent, 
disappearing before the asci are mature. 

ASCOSPORES. 

The ascospores furnish one of the most marked characters for the 
separation of the genus into sections (Plate XVII). In section 1 
they are more or less cylindric and sometimes curved. In section 
2 they are more or less elliptic, being broadest in Endothia para- 
sitica and narrowest in E. fluens and E. longirostris. The greatest 
variation in size and shape of ascospores occurs in E. fluens, as in- 
dicated by the measurements given in Table II. Anderson (1), Clin- 
ton (18), and Heald (39) describe and figure the ascospores of E. 
parasitica as very obtuse and constricted at the septum. The writers 
have but rarely seen spores of this form. This may perhaps be due 
in part to different methods of treatment or to the age and condition 
of the material. Most of the ascospores studied by the writers have 
been mounted in the fluid medium described on page 30. Fresh 
specimens have also been studied in water mounts, but with the 
same general result. The writers are of the opinion, therefore, 
that the figures of the authors cited above do not represent the most 
common and characteristic form of ascospores of this species. (Com- 
pare Plate XVII, figs. 7 to 15.) 
43737°— Bull. 380—17 3 



34 



BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 











,_, 


Oi 


w 


O0 05 00 01 


,_, 


WO 


r* 


COO 


OS 




1 2 




OS 


—< 


§ 


II °°° 






13 




O OS OS 


OS OS OS OS 


l^ CS © OS© 

ii tH 


wo 
00 


5 ii ■»« 


S * 






o 






















e 
















li 










>o 


















































CO 


— X 






,_, ; 




CO^t 


















"? 




















H H 


















** 






















1 




; 














LO 


0C CN 


: .o 


-t- X r- Oscn 


o r^ 


\ ~f \\ '-O^V 


c 


coo 






? 

o 
u 
o 


■* 








CN r-^a 


CN CiO *— 


CO 
CN CC 




1-1 


"^ 


















CJ 


















^ 


C?r*r-'C 


O 51 O f"^ 


CN t^ I t- II cicr- 


M 


t~o 






I 


so 








T* tft t}< CS 


•f ca co ^.u; 


§c 


»J5 Wil 






s 
o 






co >h ei 


MCfH 


t^ wo CO Nr> 


CN t^ I OS || C~0 


f^ 


9i~ 










US 


CN ^f CO 


CN -^C" 




CM CM 


ri 


WJCN 






•3 


CO 






CN ^ 






















Cv 












£ 


























































<M wo ' 
















CNCN 






















■^ tH 




































IN 


















O II 














d 






f. t-» 








































CM 


iO e« 






































5 












































E 






















































































u 




wo 




CD 






































o 














































g 




1-1 


































1 








60 

a 
cs 




IN 




- : 














•H 




o | 






1 






o 


i 








































^ 

£ 


wo 


_ 
















CN 




coco 






1 






'So 




jj 






















o 














| 




























g 


*f CM ' 


- 1 


- 




rt rH rH 


WOCO 

o* 


rt 


•H 






o 


03 






















































Si, 


a 




W0 


W5 CN '• 














CO -Hi- 


cot^ 














00 

© 

60 


a 




o 


















c 


1 
















t^. i-l 


CN 




4* 






t^ CNO 


I^C 


i 


II ^ 




II ' 




"5" 


a. 

CO 




o 
























: 




W 


t-4 


^ 














































1 


0) 


CO 

9 


ICO 


£ -3 '• 


MHMO 




^H CD 00 w 


> COC 
CO 


a 


"H 




■ 




I 


CD 


o 
o 


OS 










Ii 


H - 






II : 




CO 


1 




N N H 


00 CO CD c£ 


.-H 00 t^ COO 


3 COC 


■S rH iflp 


C£ 


H 




3 




os 


<N CM 




r-l il - 


4 O 


; 








« 

V 


£ 


5 

60 












H | 








^ 




W0 

oo 


ei co i-< 


00 OSCN — 


W0 CN t-l •*! ' 


3 r^ o 


3 - | 


00 0( 


) CC 


O CD 






e. cm 


i-l CM 5 


ii JO CMi- 


4 WO 
1 


i 










1— I 




CO OS W0 


00 CO 00 O 


J CO OS CO 00 c 


S COw 


5 CO O w 


) w 


"* 








00 


1-1 


HH «" 


„ ^H rir 


4 CO 


5 




■in 


w 






















J 






















M 




WO © *d< 


WS .*<[-« 


M » « 00S| 


? Tfi CJ 


t^ 


1—1 CI 


T 


1 eoos 








^ 


ii 7-H CN 


CNOlcN *■ 


< 8f H H Ht 


' 2c 

e 


CN 
-4 












t-h CO CO 


CN OSCN C 


5 wo oo oo oe 


1 CD CI 


5 GO 


O50 


E 


00-Cfl 








r~ 


OS 




4 CN rt lli- 


4 CN 


s *' 




4 P 


1 CN CN 




lO 






WO 


CD 00 CO C 


4 r» io 






H WO ". 


S< en 


COC 


4 W 


5 ©■* 






















wo 
















«5 
















cj 


: 
















■ CM 


WO CM CO 




■ CN 






H CO C 


D -^i 






M T 


4 cor* 








CO 


















CN 

C 


4 


















r^ 




oscn t-H r- 


t^. wo co r~ » 


CO 






CN CI 


3 










d 




OS 




NO-tf 


CN ii wo CO i 


o 






ooc 













fc 








r- r~ l~ I 


OS t^ CO CD c. 


D 






• t^ c 















|H 






■* rt i( tH ili- 








. rt^ 
















s 


:.a 


:g : 


03 • 
0) • 

9 i 

1 : 

g s p 






! $ i S c - ) ' m 


: o" 










: oT ; 












i 

s 

1 

t) 

$ 

p. 

02 




'3 
c 


• c3 •■•=■ ; 


i 


! c 


: 2 ; p,-, - B 
; .3 : ea^ ca . 

: Scao-pof 
• ^* «^. . 

8 m -_ J5 ^ J 


:H 

H s 

cf CD 










. .. C3 Jg 

= |ia 

! |-° B 

o a a s 






ci 








C3 cO(Jm o • 
b >-. co B 'i B 


53 ..834 


8 j 


► 1 SX-O co w & c- 
. o i «8<J « S * 


-. 


? "o 


; 
i 


• c3 s a s 
a .2 -s 5 o 

a T3 co co^ 

J g So « < 


3 "t 


: ;/ ° 

! .i o 

; £2 


'3 

'J 










03 -^2 Oh jj •" cj (8 S S g'* 




H ? 


3 -a 2 2f 

P. q=! 


5 1 


i ISS 










§§g w -g§ 2Bo?§o\ 


ec 


E 












a o3 M . cc -g, ja a "a 


330 fn o o 
































W 


H 


03 


H 








w 














P 


q 


a 






s 





ENDOTHIA PARASITICA AND RELATED SPECIES. 



35 



ss 


O if>-T 


CO 1 IN 












X if 


OS 00 i- 


OS o 


















OS Os OS OS l~ OS to 


O OSC 


OS 














o 














•* 




OS— i 


■o os ostr: 


OSCN 


























1 ,_ 






|| 
















— ' C* 






















































CO 






















1 




O II 














B9© 


01 SiOi-t 


1 S"* 










,_, 


HH 




com 


















-TlO 


if) CC lS C 


CO if 

If 




CO 












o 




"II 
















l- Nrtp* 


o a 










^Hr-I 


CO 


■-< if) OS 1 CI CO r- 
















■*<M 








CO 












© 




































COi- 




















tfSrt 


to 


CO 


OSCV 


. 


OS 






CO CO 


CO 




CO ^Cn 


oso II 




















c 


fii 


CO* 
















CO 






















■n 




















































£ 


00 






ITCCO 


to 




coc 


- 1 CO OS u- 


) l~l^ 






CO 


CO IO 




















o 


co' 












<C- 




If) 1 






o 




















£ 








co co cow 


- 


o « 


> 1 -<** C*3 t> 


cor~ 






,_, 






































CO 




























C 


IN 






















o 














































































































CO 


Tf 0C CO 50 


V 


— . tr 


to© c 


s os^ 


• Ii 


























o 


CO* 




""* 




IT 


<N- 


M co 

--' h 










































































































fl 


IO 




tO *-l I— CO ^H tc 


■* c 




-fO II 










































































00 || 






o 




















■S 
















































































-r 


o 


OClSOC CRCO — 


tH t~ 


1 coor. 


o -r II 


































•«< 




























CO 


































ao 














II 
























a 








































CO 


OS 


if CM -* I- CO — 


if tc 


CNC0O 


to - 


1 CO 






























































IN 




































.C 






















































if; i- 




CM 




50 — -+ o co r- 


OS- 


coooc^ 


co- 


1 coaooc 


' s° 












| 
























IN 








































CO TT- 


^ "*r co 


00 Cs 


& 




,, 


00 CO CO coco tc 


S CO 




1 H« 


3 O00IMO 




































CO 






c 






































Pt 


















OS CO 


CO r» c*- 


t>- ** 


fc 




o 


00 .iCO O50Qf 




-H>-H C 


> ifJC 


> 1 <N CO -^ l" 


-* ■* 


~* 




c 


1 


CO 


rt 


— -< -«,__ 


c 


> 


1-1 „. 




OS . 






















CO 


























oo 


oo wotc 


CSC 


£ 


OS 


to 


50 to O' ^ 50 Lr 


r~c 


S -tf 


e> 


i toe 




O *J< 




-*,-( 


c 






"" "■* "~ - 


o 


' 




c 


WWMff 


CO . 


























CO 


sSiS 


00 ^--<<X 


00 -<T 




00 


CO 


CO CO ■* CO to -1 


co a 


S If) 




If) t> 


NOGC1 


■ceo 


eeos 


•-I e»N« 










c 










to . 
to 


MN 


50 Osrjl t£ 


COtC 






,_, 


CO 


,_, 


,_( 


-t< [ 












| HMOr 






oi '-'eo 1 ^ 


f-H IT 
CM 




-■ 










c 














CO . 


OS OS 


00 lOtDC 


Osr^ 




to 
































COCO 


























































~ 






































coo 


r>- 00 t^ CO 


■* 








OS if) CO -H t~ t~ 

co — i o -*eo c 

I^I^I- l- OS I- 






to r- if 
to to tc 






-H00 OSC 
IO in CO i- 


















rt^H^rfrf _ 






r ~ i Hr " 




















CC 00 r~ 


00 -<t 






















































































































a 


































































































03 
































































c 




























a 


























■a 




























■O lOMr- 








































































































CO HHt- 






1 


3 

s 


03 











































, 










j 




























>s 
















a 












s> 


























c 
















3 










i 


J 




























s 








































































a 


03— ' 03 








1. 




























a 
















03 

t/3 


ii Castanea dentat 
From Pantanel 
Gordonsville, V 









3 


as 












c 










d 


03 
CO- 












O 

2 c 
2> 


- 


o3 c3 ;_ 
SI* 


"3 
c 


a 

a 

- 






w ..C 

"3 e'e 

3 flr* 

c9 C 1 - 

i-.Sc 


£ 


o 

E 

B 

1 


r 

T 


c 
- 
J 


c 


03 

_o 

as 

s 

"3 ^ 

o a 


go 
=3^ 


>> 

o 
E 




- 


as 

p. 

o 

&a 

_r a. 

5 

o s 


:hia parasitica: 
n Castanea sp., 
rom Pantanelli 
ordonsville, Va 
denton.Md 


03 

c 
Eh 


c 

as 
o 

as 




On <SO O 












°C0-O 








a 










n 




a 




H 






1*1 
















X 




■~ 
















w 










W 















36 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

PHYSIOLOGY. 

CULTURAL STUDIES. 1 

During the past three years the writers have had tinder observation 
more than 4,000 cultures of the several species of Endothia on more 
than a dozen artificial media, as well as on sterilized twigs of many 
kinds. Throughout this work the writers have been impressed with 
the uniformity of the behavior of the organism in culture and the 
certainty with which the various species could be distinguished on 
any of the media used. 

Cultures of Endothia parasitica, for instance, from specimens sent 
from China or British Columbia were absolutely indistinguishable 
from cultures made on the same medium from local material. 
Transfers made from stock cultures which had been kept on artifi- 
cial media for two years were identical with transfers from freshly 
collected material. The same remarkable constancy held for the 
other species. Cultures from material collected in different localities 
or from different hosts were identical, not only in appearance but, so 
far as the writers were able to determine, in temperature and moisture 
relations also. As previously noted, this is in marked contrast to the 
senior writer's experience with the species of Glomerella and it is 
believed differs from the experience of many investigators of fungi. 

No less striking is the certainty with which the several species may 
be distinguished on any medium tried. Endothia parasitica, E. 
tropicalis, and E. flicens and its variety mississippiensis are very 
closely related morphologically. Moreover all except E. parasitica 
have, as near as could be determined, much the same relation to their 
hosts. Yet each species has distinctly and readily recognized charac- 
ters on culture media. 

It should not be imagined, however, that the differences are 
recognizable at once as clearly distinctive characters. The differences 
at first glance might, readily be considered fluctuating variations. 
But the fact that the characters remain constant through hundreds 
of generations and have never varied toward one another makes 
them worthy of recognition as specific characters. 

In a previous paper (77) the writers described their results with 
cultures of Endothia parasitica, E. fluens, E. fluens mississippiensis, 
and E. gyrosa on a number of culture media. At that time the work 
of other investigators was reviewed and the methods of preparing 
the various culture media and making the cultures described. Since 
the publication of that paper, however, cultures of two more species, 
E. tropicalis and E. singularis, have been secured and about 2,000 
additional cultures of the various species made. In addition to the 
culture media mentioned in the previous paper (77, p. 10), the writers 

1 The cultures described were all grown at ordinary laboratory temperatures in the 
winter, about 20° to 24° C. 



ENDOTHIA PAKASITICA AND RELATED SPECIES. 37 

have grown the organisms on sterile twigs of many species and on 
liquid media. 

As stated above, the various species of Endothia are distinguish- 
able on any medium tested. White corn meal in flasks has, however, 
been most used by the writers in identification work and for keeping 
stock cultures. All the species grow readily on this medium and may 
be determined with certainty within 10 days under ordinary con- 
ditions of growth. In addition, the medium is cheap, easily pre- 
pared, and does not dry out so quickly as agar media in tubes, so 
cultures may be kept alive much longer without transfers. Almost 
equally good for purposes of identification are rice and oatmeal in 
flasks, corn-meal agar, and potato agar. 

The distinguishing characteristics of the various species in culture 
have been described rather fully in the previous publication and may 
be brieffy summarized, as follows: 

CULTURES ON CORN-MEAL AGAR (UNSLANTED TUBES). 

Corn-meal agar proved the best agar medium for the production 
of pycnospores and showed constant differences in the cultural 
characters of the various species. The most characteristic differences 
appeared in cultures from six to eight weeks old on unslanted 
tubes. (See PI. XXI, figs. 2 to 7.) 

Endothia gyrosa at this age showed a rather abundant, felty white myce- 
lium, flecked with eapucine buff, but there were no pycnidia. In older cul- 
tures small pycnospore threads were sometimes produced. Usually before the 
cultures were 10 days old the medium was changed to a delicate lavender 
just below the mycelium, and below this to a light olive green. A few days 
later the lavender disappeared and the green deepened to olive green. 

Endothia singularis grew more slowly than any other species. Within 
three weeks, however, the mycelium covered the entire surface. It was 
smoother than E. gyrosa and nearly white, with raw umber spots where the 
mycelium touched the glass. The medium was changed to a light hellebore 
green one-half inch below the top. 

Endothia flitcns, as pointed out in the previous paper, produced an abundant 
deep-chrome mycelium, with usually one or two rather small pycnidial pus- 
tules. 

Endothia flucns mississippiensis produced a scant surface growth of my- 
celium, between cadmium yellow and raw sienna in color. The upper one-half 
centimeter of the agar became reddish orange. The pycnidial pustules were 
more numerous than those of E. fluens, but smaller and more scattered than 
those of E. parasitica. 

Endothia longirostris at the end of six weeks had a scant, webby, orange, 
aerial mycelium growing against the glass. Mycelium on the surface of the 
medium was very scant, orange to cadmium yellow in color, with scattered tiny 
xanthine orange to orange spore masses. The color of the agar changed to 
medal bronze just beneath the mycelium, shading into orange citrine below. 

Endothia tropicalis at the end of six weeks showed a thinly felted mycelium, 
white to eapucine orange, with numerous small, scattered pycnidial pustules. 
The ring of mycelium against the glass was light orange yellow, as contrasted 
with white in E. parasitica. 



38 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

Endothia parasitica gave a scanty white growth of surface mycelium, with 
several prominent pycnidial pustules clustered near the center and of a slightly 
darker shade than the " raw sienna " of Ridgway. 1 

CULTURES ON POTATO AGAR (SLANTED TUBES). 

Potato agar was used by the Andersons (3) to distinguish Endo- 
thia parasitica from E. fuens. The writers have used it extensively 
and found it a very useful medium for distinguishing the species. 
As stated in the previous paper (77, p. 11), however, unless this 
medium was very carefully prepared it varied greatly in acidity 
and probably in other respects, with resultant variations in the 
behavior of the organisms. Spore production was not so abundant 
on this medium as on many others. The preparation of this and 
other media is described in the paper cited. 

Endothia gyrosa. — This species developed rather slowly, producing a fairly 
abundant aerial growth, which was felty rather than fluffy. The color was 
white, flecked with capucine buff, and no spore masses were produced. 

Endothia singularis. — This species grew even more slowly than E. gyrosa. 
On cultures made from conidia, growth was hardly perceptible at the end 
of three days. Mycelial cultures at the end of one week showed less growth 
than E. gyrosa, but did not differ greatly from it in either color or texture. 
At the end of one month the mycelium was slightly more fluffy and decidedly 
less in amount than that of E. gyrosa. Most of the surface was a very light 
buff color, with sometimes a few spots of capucine orange to English red. 

Endothia fluens. — Pycnospore streak cultures of this species varied some- 
what as to the amount and time of appearance of color, probably due to the 
variations in the acidity of the medium referred to above. Many tubes 
showed an orange color in one week, while others produced no orange what- 
ever. In no case did cultures of E. fluens produce the " brassy " metallic sur- 
face appearance so characteristic of E. parasitica. Pycnidia were few and more 
scattered than in E. parasitica and did not begin to appear until the third or 
fourth week. A slight amount of warbler-green color sometimes appeared in the 
medium at this age, but never so conspicuously as in E. parasitica. 

Endothia fluens mississippicnsis. — This produced a less fluffy aerial mycelium 
along the spore streak than E. parasitica. After five or six days the fungus 
showed an orange color by transmitted light, and was indistinguishable in 
this respect from E. parasitica. The character of the surface was somewhat 
different, however, and by reflected light appeared xanthine orange. When 
two weeks old this form differed still more markedly from E. parasitica in 
color, being grenadine red by transmitted light and showing no spore masses. 

E. tongirostris. — At the end of one week this produced a white, fluffy growth 
scattered in small patches over the surface of ^be medium. This later became 
rather close in texture, especially near the base of the agar slant. No spores 
were produced on this medium. 

Endothia tropicalis. — At the end of one week this showed less growth than 
E. fluens, covering about a third of the surface of the medium, while the 
other covered nearly the entire surface. The mycelium was closely matted 
and a very pale buff (paler than any in Ridgway). At the end of one month 

1 In the descriptions of cultures comparisons were necessarily made with cultures in 
flasks or tubes. This of course made comparison more difficult and somewhat less accurate 
than if the material had been removed from the container. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 39 

E. tropicalis covered the entire surface with a thin layer of surface mycelium, 
considerably darker in color than when one week old. 

Endothia parasitica. — At the end of three or four days at room temperature 
this showed a short, fluffy, white, aerial growth along the streak. The surface 
of the mycelium was orange by transmitted light, while by reflected light it was 
between raw sienna and antique brown at the sides. Within six days the 
mycelium, especially at the base of the agar slant, took on a peculiar metallic 
"brassy" appearance, clue apparently in part to the character of the mycelium 
and in part to the minute water drops scattered over the surface. This 
portion of the culture was light orange yellow by reflected light and orange 
by transmitted light. This metallic appearance has been found to be the 
most constant and reliable distinguishing character of E. parasitica on potato 
agar. In 12 to 14 days small pycnidial pustules appeared in the upper portion 
of the tubes, and the agar just below the mycelium became warbler-green, 
changing later to olive green. 

CULTURES ON CORN MEAL (IN 100 C. C. ERLENMEYER FLASKS). 

Endothia gyrosa. — Mycelial cultures one week old showed a growth of rather 
compact mycelium covering nearly one-half the surface of the medium. The 
mycelium was ochraceous buff near the point of inoculation, shading into 
white at the margin. There was no discoloration of the medium and no spore 
masses were seen. 

Cultures of the same kind one month old showed an abundant, rather thick 
growth, having the surface mostly covered with somewhat irregular tubercular 
masses, suggesting immature pycnidial stromata similar to those found in 
E. radicalis, but smaller and producing no spores. The surface of the culture 
was capucine buff, that of the tubercles honey yellow to Isabella. The dark 
color was apparently due in part to numerous superficial water drops. A por- 
tion of the medium was changed to perilla purple. 

Endothia singnlaris. — Mycelial cultures one week old covered only one-third 
of the surface. The growth was mostly white and fluffy, with ochraceous buff 
near the center. 

At the end of one month the growth bad entirely covered the surface. The 
mycelium varied in color from cadmium orange to capucine buff, the color being 
distributed over the surface in patches. The corn meal was changed to perilla 
purple near the center. No spores were produced. 

E. singnlaris was readily distinguishable from E. gyrosa, which it resembled 
more closely in culture than any of the other species, by the rate of growth and 
the color and nature of the surface of the mycelium. E. singnlaris grew more 
slowly than E. gyrosa, was rather brighter in color (cadmium orange), and 
the surface of the mycelium was decidedly more even, lacking the tubercular 
masses characteristic of E. gyrosa. 

Endothia fluens. — Cultures at the age of one week showed a growth of 
loose, fluffy mycelium covering one-half of the surface of the medium. The 
mycelium was deep chrome to light orange yellow at the point of inoculation, 
passing through perilla purple and light pinkish lilac and fading into white at 
the margin. Occasionally the medium was changed to perilla purple near the 
center. No spores were present. 

Cultures one month old showed a compact growth, with a nearly smooth 
surface. The color ranged from light cadmium to empire yellow. The whole 
mass of the medium was perilla purple. Spore masses were rarely present at 
this stage, but shortly afterwards a few large erumpent stromata were formed, 
which extruded spores in thick masses. 



40 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

Endothia fiuens ?nississippiensis. — Cultures one week old showed an orange- 
chrome growth a little more than half covering the surface of the medium. 
The superficial growth was very similar to that of E. parasitica. There was no 
discoloration of the medium and no spore masses were found. 

The same organism one month old produced a growth with a compact, rather 
uniform surface, the superficial portion having a coarse, matted, webby appear- 
ance, which was most noticeable about the margin. The color of the mycelium 
was cadmium orange to xanthine orange, while that of the medium was un- 
changed. Spore masses were much more numerous than in E. fluens, but 
smaller and less numerous though very similar to those of E. parasitica. 

E. longirostris. — Cultures one week old covered about one-third of the sur- 
face of the medium. The mycelium was short, fluffy, white, with only a tiny 
spot of cadmium orange near the point of inoculation. At the end of six weeks 
the entire surface was covered with a compact growth rather uniform in tex- 
tui*e, cadmium orange to xanthine orange in color. The surface was irregularly 
ridged, giving it a wrinkled appearance, with tiny mars orange spore masses 
irregularly scattered over the surface. This species closely resembles E. fluens 
mississippiensis on this medium, being distinguished from that variety by the 
smaller and much less numerous spore masses. The medium is changed to 
amber brown just below the mycelium, shading into mars yellow in the lower 
portions. 

Endothia tropicalis. — At the end of one week this showed less growth than 
either E. parasitica or E. fluens, covering about a third of the surface. The 
mycelium was matted close to the surface and was a very pale buff (paler 
than any of the buffs shown in Ridgway). No pycnidia were present. 

At the end of one month's growth the surface was entirely covered with 
a closely felted mycelium and small, numerous, thickly scattered spore masses, 
more closely resembling those of Endothia parasitica than any other species. 
The mycelium was orange buff to apricot orange, and orange chrome against 
the glass. The color of the medium was unchanged. 

Endothia parasitica. — In cultures one week old the growth on corn meal 
covered about one-half of the surface of the medium. The outer margin was 
pure white, the remainder buff yellow below, with a superficial white growth 
above. A few small pustules with spore masses occurred near the point of 
inoculation. The medium was uncolored. 

Cultures one month old showed a compact growth, nearly smooth on the 
surface. The superficial mycelium was pale orange yellow. The pale yellow- 
ocher spore masses were minute, very numerous, and nearly covered the sur- 
face. The medium was slightly greenish about the sides of the flask just 
beneath the mycelium. 

DISTINGUISHING CHARACTERS OF THE VARIOUS SPECIES ON CORN MEAL IN FLASKS. 

The color reactions of the various species on corn meal are very 
striking. Endothia fiuens (PI. XXI, fig. lb), as noted above, 
changes the whole mass of the medium to perilla purple in less than 
a month. E. gyrosa and E. singularis also produce this color change, 
but somewhat more slowly. E. fiuens mississippiensis, E. tropicalis, 
and E. parasitica, on the other hand, in hundreds of cultures have 
wholly failed to produce any purple color. This furnishes an easy 
and reliable method of distinguishing E. parasitica from E. fiuens 



Bui. 380, U. S. Dept. of Agriculture. PLATE XVII. 



i ' s> f\ •* ;• 



* 1 2 3 4 5 



< 



\ 



\ 



» 






i V /■ w # J 



-67 10 






•0 



' 11 12 13 14 15 




PHOTOMICROGRAPHS OF PYCNOSPORES AND ASCOSPORES OF 

ENDOTHIA. 

Figs. 1 to 6.— Pycnospores: 1, Endothiagyrosa; 2, E. sinqularis; 3, E. fluens; 
4, E. longirostris; 5, E. parasitica (American); 6, E. parasitica (Chinese). 
Figs. 7 to 1 5.— Ascospores: 7, E. gyrosa; 8, E. singularis; 9, Sphaeria radicalis, 
from Schweinitz'S Specimen in Fries's Herbarium; 10, Endothia pseudorad- 
icalis; 11, e. fluens; 12, e. fluens mississippiensis; 13, e. longirostris; 
14, E. tropicalis; 15, E. parasitica. 



Bui. 380, U. S. Dept. of Agriculture. 



PLATE XVIII. 




Endothia parasitica on Plate Cultures of Corn-Meal Agar 4 Weeks Old. 
The Upper Plate Was Kept in Total Darkness; the Lower Plate in the 
Direct Light of a North Window. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XIX. 




ENDOTHIA SPECIES ON WHITE CORN MEAL (10 GRAMS OF CORN 
MEAL TO 20 C. C. OF WATER). CULTURES 2 MONTHS OLD. 

Fig. 1.— Endothia gyrosa; Fig. 2.— E. singularis; Fig 3.— E. fluens; Fig. 4.— 

E. FLUENS MISSISSIPPIENSIS. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XX. 










i 








ENDOTHIA SPECIES ON WHITE CORN MEAL (10 GRAMS OF CORN 
MEAL TO 20 C. C. OF WATER). CULTURES 2 MONTHS OLD. 

Fig. 1.— Endothia tropicalis; Fig. 2.— E. parasitica; Fig. 3.— E. longirostris. 

















7 



M.S.Haifl. 



CULTURES OF ENDOTHIA SPECIES 



mont^s> C rowt"of^XL; 5 m0nth ' S ^°^ ° f ***>**» Parasitica; b. corn meal after i 
Pm?-P^T ° n » P *' iffht ™^ S 0f «r«-meal agar 6 weeks o- 



ENDOTHIA PARASITICA AND RELATED SPECIES. 41 

(PI. XXI, fig. 1) in field work when fructifications of the species 
are wanting or doubtful. 

Aside from the differences in color, the most conspicuous and 
important characteristic of these fungi in corn-meal cultures is 
found in the fructification. Clinton (18, pi. 26) has already men- 
tioned and illustrated similar differences in cultures of these organ- 
isms on agar in Petri dishes. In Endothia parasitica the pycnidia 
and spore masses are small, numerous, thickly scattered, and em- 
bedded in the mycelium. E. fuens, on the other hand, forms few, 
large, erumpent stroma ta, with spores extruding in thick, elongated 
masses. E. tropicalis closely resembles E. parasitica in number, size, 
and arrangement of pycnidia and spore masses, but differs in color 
of mycelium. E. fluens mississippiensis appears somewhat inter- 
mediate between E. parasitica and E. fluens in regard to the character 
and abundance of the pycnidia and in color of the growth. These 
peculiarities have been very uniform and constant in all the cultures 
on this medium and if they could be coordinated with regular mor- 
phological differences in nature would justify the separation of this 
form as a species. (See Pis. XIX and XX.) 

CULTURES ON LIQUID MEDIA (IN 100 C. C. FLASKS). 

Some difficulty was experienced at first in growing the species of 
Endothia satisfactorily on a liquid medium. Abundant growth was 
obtained on a medium suggested by Dr. Mel. T. Cook. This is a 
modification of the liquid medium No. II as given by him (19). 

Cook's liquid medium, No. II, is prepared as follows : 

Into 500 c. c. of distilled water put 15 grams of glucose and 20 grams of 
peptone steamed at 100° C. for three-fourths hour ; into another 500 c. e. of 
distilled water put 0.25 gram of dipotassium phosphate and 0.25 gram of 
magnesium sulphate, steamed for 20 minutes ; filter both 500 c. c. into same 
receptacle, steam 10 minutes, put into flasks, about 30 c. c. in each flask, and 
autoclave. 

All species grew readily on this medium, Endothia parasitica even 
producing pycnospores. At the end of one month's growth the sev- 
eral species were readily distinglished on this medium and may be 
briefly described as follows: 

Endothia gyrosa. — Growth scanty ; did not form a continuous mat, but re- 
mained in small bunches, giving an almost flocculent appearance. The mycelium 
appeared white when removed from the culture solution, but the solution itself 
was honey yellow. 

Endothia singularis. — Growth even less abundant than E. gyrosa; formed 
small brown knots against the glass. Mycelium buff, and the medium was 
changed to honey yellow. 

Endothia fluens. — Growth somewhat more abundant and less closely matted 
than E. parasitica, entirely submerged ; mycelium white ; liquid unchanged in 
color. 



42 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTUEE. 

Endothia fluens mississippiensis. — Growth slightly less abundant than in 
E. parasitica; submerged except at the very edges; much lighter in color, being 
reddish brown. 

Endothia tropical is. — Tins differed markedly from either E. parasitica or 
E. fluens. The mycelium formed a thin felt over the surface, white to salmon 
orange in color, with no change in the medium. 

Endothia parasitica. — Mycelial growth very abundant, closely matted, chiefly 
submerged, but slightly arborescent in one or two small areas, which remained 
above the surface. Color, dark greenish brown. 

CULTURES ON STERILIZED TWIGS (IN TUBES). 

Early in this work it was noted that all the species of Endothia 
grew readily on sterilized chestnut twigs in test tubes. Later, tests 
were made with twigs from a number of common, woody plants. 
Twigs of Acer saccharum, Alnus rugosa, Betula papyri/era and B. 
lenita, Carpinus caroliniana, Cornus florida, Fagus grandifolia, 
Fraxinus a?rbericana, Ostrya virginiana, Populus grandidentata, 
Primus serotina, Rhus glabra, Tilia americana, and Tsuga canadensis 
were collected in New York State early in June, placed in test tubes 
with a few 7 cubic centimeters of distilled water and sterilized in an 
autoclave. All the species of Endothia were tested, and all grew on 
every species of twig except Tsuga. The difficulty of completely de- 
scribing this series may readily be seen from the fact that each species 
of Endothia had a different appearance on every kind of Avood. 

In general it may be stated that Endothia gyrosa and E. singularis 
grew more slowly than the other species and produced no spores, 
while all the other species produced spores on most hosts. The 
mycelium of E. parasitica was usually white, especially on the bark. 
E. gyrosa and E. singularis produced various shades of buff, while 
E. fluens, E. fluens mississippiensis, and E. tropicalis developed a 
much more brightly colored mycelium, usually showing yellow or 
orange shades. 

MOISTURE RELATIONS. 

In an earlier paper (77, p. 7) the writers reported tests with 
Endothia fluens and E. parasitica on media containing various per- 
centages of water. It was observed that pycnospore production 
began earliest and was most abundant on the media containing the 
least moisture. 

Aside from this the writers have thus far been unable to make 
definite tests as to the moisture relations of these fungi. However, 
incidental observations in connection with the light tests (p. 43) and 
temperature tests (p. 45), as well as results of field experiments, 
particularly those at Woodstock, N. Y., make it apparent that the 
amount of available moisture is a very important factor in the 
fructification of the fungus. 






ENDOTHIA PARASITICA AND RELATED SPECIES. 43 

LIGHT RELATIONS. 

The relation of light to pycnospore production in Endothia para- 
sitica was first discussed by Anderson (1, p. 20). He says — 

When plate cultures are grown in total darkness on chestnut-bark agar, no 
pycnidia are developed, while on plates made at the same time and grown 
in the light, the usual rings of pycnidia appear (fig. 57). Experiments were 
also tried in which the plate was left in darkness until about half covered 
with mycelium and then brought into the light. Circles of pycnidia were 
developed, beginning with the ring which marked the outermost limit of the 
colony when removed from the dark chamber. The concentric rings which 
always appear on agar cultures are due to the alternation of night and day. 

Later, in a bulletin by Anderson and Rankin (6, p. 592), the same 
results are attributed to D. C. Babcock. 

Up to the time the above-mentioned work was published the 
writers had grown about 3,000 cultures of the several species of 
Endothia on various media in flasks and tubes. Practically all of 
these cultures had been kept in dark cases and Endothia parasitica 
had produced pycnidia abundantly on most of the media used. It 
seemed desirable, therefore, to determine whether wholly different 
light relations existed when the fungus was grown on plates. The 
following series of tests was accordingly made, using E. parasitica 
only. 

LIGHT TESTS OF CULTURES ON PLATES. 

In experimenting with plate cultures in order to check up the 
results reported by Anderson and Rankin (6, p. 592) it was noted 
that there was great variation in the rate at which the cultures 
dried out. There was considerable variation in this respect in dif- 
ferent plates kept side by side, apparently due to differences in the 
Petri dishes, and a marked difference between cultures kept in 
light and those kept in darkness. Since a causal relation between 
lack of moisture and abundant spore production had already been 
shown, it seemed probable that this might influence the results of 
the light tests in plate cultures. In fact, in a few cases the cultures 
kept in the light did produce spores earlier than those kept in dark- 
ness. Accordingly, in order to eliminate at least in part this fact 
which seemed to obscure the possible effect of light, a method was 
sought of equalizing the loss of moisture. In the following series 
half the plates were placed under a plain bell jar and the other half 
under a bell jar of equal size but darkened by being covered inside 
and out with heavy black paper, such as is used to wrap photographic 
plates. The two bell jars were then set side by side in front of a 
north window. By this means the conditions were made much more 
uniform as to temperature and moisture. There was still a slight 
difference in the rate of drying and undoubtedly at times a difference 



44 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

in the temperature of the light and dark plates, but probably not 
sufficient to interfere seriously with the experiments. 

Series 1. On corn-meal agar plates under bell jars. — In nine days 
there was no distinguishable difference between the plates in light and 
darkness, a few spore masses occurring near the middle of each. 

In 18 days most of the light plates showed a central ring of spore 
masses and a zone of scattered spore masses near the edge. The dark 
plates showed a few small spore masses near the center, and scat- 
tered about the outer portion were the small masses of mycelium 
which usually constitute the early stages of pycnidial formation. 

In 30 days the number of spore masses had increased somewhat in 
both sets of plates, but more in the darkened plates, so that the 
number of spore masses was about equal in all the plates. The two 
sets of plates were fairly uniform as to the arrangement of the spore 
masses. Plate XVIII shows a typical example. 

Series 2. On chestnut-twig agar plates under bell jars. — After nine 
days the cultures in light and darkness were alike. No spores had yet 
appeared in either set. 

In 30 days there were a few spore masses on nearly all of the 
plates, there being no difference between those in light and those in 
darkness either in number or distribution. 

Series 3. On corn-meal agar and chestnut-twig agar under bell 
jars. — In this test the plates were piled alternately, first a corn-meal 
and then a chestnut-twig agar plate, so that the two media would be 
under conditions as nearly identical as possible. The plates were 
inoculated as before and left untouched for 18 days and after that 
were examined daily. After 18 days all the corn-meal plates showed 
spore masses in practically equal numbers, while the chestnut-twig 
agar plates showed no spore masses whatever. There was no ap- 
parent difference in the growth on either medium between the plates 
in light and those in darkness. 

At the end of 25 days the cultures on chestnut-twig agar plates 
showed numerous small masses of mycelium, indicating the forma- 
tion of pycnidia. No difference was perceptible between the dark 
and light plates. 

In 28 days, from 100 to 150 of these pycnidia in each plate were 
extruding spore masses. The light plates showed in general a larger 
mass of spores than the dark plates, but this was not marked, cer- 
tainly no greater than was accounted for by the unavoidable dif- 
ference in radiation and the consequent difference in moisture. This 
difference in the moisture of the medium was clearly shown each 
morning by the greater amount of moisture condensed on the covers 
of the darkened Petri dishes. 

At this time (after 28 days) four corn-meal agar plates which had 
been wrapped in four layers of heavy black photographic paper and 



ENDOTHIA PARASITICA AND RELATED SPECIES. 45 

placed on a window sill were opened and examined. In spite of the 
cold weather prevailing during this test and the consequent low tem- 
perature of the room at night, these plates contained an average of 
nearly 200 well-developed spore masses. 

At the end of 35 days the chestnut-twig agar plates which had 
been kept in the light showed an average of 160 spore masses, while 
those kept in darkness showed an average of 130 spore pustules, a 
comparatively small difference in favor of the light plates. There 
was, however, a wide difference between the various plates in each 
series, and it was impossible in most cases to distinguish cultures 
grown in the light from those grown in darkness either by the num- 
ber, size, or arrangement of the pycnidia and spore masses. 

From these experiments it is evident that pycnidia are produced 
abundantly in total darkness on chestnut-twig agar as well as on 
other favorable media. There is no perceptible difference in the 
amount of spore production or in the arrangement of pycnidia be- 
tween cultures kept in total darkness and those kept in the light 
during the day if the temperature and evaporation remain the same 
in both. Continued observation of numerous cultures grown both 
in daylight and in darkness has convinced the writers that light has 
no perceptible effect on mycelial growth either in amount, nature, or 
color production. It seems evident, therefore, that light is a neg- 
ligible factor in the growth and fructification of these fungi. 

TEMPERATURE RELATIONS. 

In an earlier paper (77, p. 9) the writers published the results of 
three series of tests made to determine the temperature relations of 
three species of Endothia. Since the publication of that paper cul- 
tures of other species and additional material of some of the species 
from widely separated localities have been secured. Four series of 
temperature tests including this new material were made on solid 
media. 

TESTS ON SOLID MEDIA. 

In these tests cultures of Endothia gyrosa, E. singulars, E. ftuens, 
E. -ftuens mississippiensis, and E. parasitica were tried on corn-meal 
agar in slanted tubes, oatmeal in flasks, and potato agar in slanted 
tubes. The cultures tested were from specimens chosen from the 
extremes of the known ranges of the fungi and from their different 
hosts. No difference could be detected in the various cultures of the 
same species, even in those from widely separated localities and from 
different hosts. Cultures appeared to have the same temperature 
relations wdiether made from spores or mycelium. The results may 
be briefly summarized as follows: 

At 41° and 39° C. there was no growth in any species. Cultures removed 
from the incubator at the end of 11 days and kept at room temperature showed 
no growth. 



46 BULLETIN 380, U. S. DEPAETMENT OF AGKICULTURE. 

At 35° C, Endothia gyrosa, E. singularis, and E. parasitica showed a slight 
development within 2 days, but at the end of 11 days it was still slight and 
abnormal in appearance. E. fluens and E. fluens mississippiensis showed no 
growth at this temperature. 

At 31° C, Endothia gyrosa, E. singularis, and E. parasitica appeared about 
the same as at room temperature for the first four days. At the end of six 
days these species showed somewhat less growth than at room temperature, 
while at the end of two weeks the growth was less in extent and markedly 
less freshly colored than that at room temperature. E. fluens and E. fluens 
mississippiensis showed somewhat less growth than at room temperature even 
in 4 days, and markedly less at the end of 2 weeks. 

At room temperature (which at this time varied from 20° to 24° C. ) the 
growth was much as described in the previous paper. Within 11 days growth 
was practically complete and in 14 days there was abundant spore production 
in Endothia parasitica. 

At 18° and 16° C, all species showed considerably less growth than at room 
temperature, but there seems to be little difference in the comparative growth 
of the various species at these temperatures. At 13° the growth was decidedly 
less than at 16° C. but was fairly normal in appearance in all the species except 
that Endothia fluens mississippiensis failed to produce the characteristic color 
at this temperature. 

At 9° C. there was a very slight growth in all species. 

At 7°, 5°, and 2° C. there was no growth whatever. Cultures removed to 
room temperature at the end of 11 days developed normally and at about the 
same rate as in newly made cultures. 

These additional tests seemed to confirm the results already pub- 
lished (77, p. 27) ; that is, growth was best in all species at ordinary 
room temperature, about 20° to 24° C. The minimum temperature 
for all was about 9°, and all failed to grow at 7° C. The maximum 
temperature for Endothia gyrosa, E. singularis, and E. parasitica 
appeared to be about 35°, while the maximum for E. fluens and its 
variety E. -fluens mississippiensis was apparently about 32° C. At 
all the temperatures tried E. singularis grew much more slowly than 
any of the other species. 

It was noted that cultures kept at 7°, 5°, and 2° C. showed no 
growth, but when removed to room temperature developed normally, 
while cultures kept at 41° and 39° C. failed to grow when removed to 
room temperature. This seemed to indicate that the fungi are more 
susceptible to heat than to cold, and such is perhaps the case. There 
was, however, the additional factor of moisture involved, for while 
the agar of the cultures kept at 7° and lower w T as in apparently the 
same condition at the end of 11 days as when first inoculated, the 
agar of the cultures kept at 41° to 39° C. was considerably dried. 
This raised the question as to whether the drying out of the agar had 
not affected the grow T th of the fungi in those cultures kept above room 
temperature as much as the higher temperatures themselves. 

The same idea was suggested by the fact that several of the species 
grew for a few days at 31° C. as well as they did at room temperature, 
and then fell behind. It seemed possible that this falling off in the 



ENDOTHIA PARASITICA AND RELATED SPECIES. 47 

rate of growth might be due, at least partly, to more rapid drying of 
the agar at 31° C, or possibly to the more rapid development 
of some toxin, as was suggested by Balls (7) to explain a similar 
observation on the " soreshin " fungus. These observations threw 
doubt upon the accuracy of the writers' previous conclusions, and 
made it seem possible that the optimum temperature of the species 
of Endothia might be well above room temperature. This could only 
be determined accurately by some method which would control tem- 
perature without altering the supply of moisture. Some months 
after the above tests were concluded it was discovered that the various 
species of Endothia would grow readily on several liquid media. 
Consequently, several series of tests on liquid media were run parallel 
to those described above, except that the tests were continued for 
only four days. Experiment showed that at the higher temperatures 
the medium became considerably reduced by evaporation if left for 
a longer period. 

TESTS ON LIQUID MEDIA. 

In the series of tests on liquid media, all the species of which cul- 
tures had been obtained were grown on Cook's medium (see p. 41) 
both in tubes and in flasks, using ten tubes and six flasks at each 
temperature. The cultures of Endothia gyrosa and E. singularis 
were made with bits of mycelium from pure cultures. The other 
species were grown from conidia and the cultures were kept for two 
days at room temperature, in order to allow the conidia to germinate 
before being placed in the temperatures to be tested. 

The following temperatures were used for making the tests: 40°, 
37.5°, 35°, 29°, and 27°, and room temperature which was fairly 
constant at about 22°, 17°, 12°, 9°, 7°, 3°, and 2° C. There was some 
variation in the temperature of the incubators and refrigerators 
used, but in most cases they did not vary more than 1 degree above 
or below the temperature indicated. xVt 40° there were occasional 
traces of growth, especially in Endothia parasitica, but this may have 
occurred when the incubator dropped to 39° C. There is no regular 
and continued growth at this temperature. 

At 37.5° C. there was perceptible growth in all the species. This 
is in striking contrast to the results on solid media, as no species 
grew at a temperature above 35° C. on solid media. 

At 35° C. Endothia parasitica showed practically the same amount 
of growth as at 27° and 29° C. for the first three days, but fell behind 
after that. E. fluen-s showed less growth at 35° than at the lower 
temperatures. These two species were the only ones tested at 35° C. 

At 27° and 29° C. growth was markedly more abundant than at 
37.5°, and in most of the species was more abundant than at room 
temperature. In Endothia gyrosa and E. fluens mississippiensis the 



48 BULLETIN 380, U. S. DEPARTMENT OF AGEICULTUEE. 

growth at 27° C. was apparently equal to that at room temperature. 
At 22° C. (room temperature) all species developed much more rap- 
idly than at the lower temperatures. At 17°, 12°, and 9° C. there 
was progressively less and less growth. At 7° C. and lower there 
was no growth whatever. 

While these tests are not wholly satisfactory and must be regarded 
only as approximations, they are of some interest. Below 7° C. there 
is no growth in any species. 

It is evident that there is a considerable range of temperature, 
from below 20° to well above 30° C, within which the species of En- 
dothia grow readily. Within this range there may be a definite 
optimum for each species, but this has not yet been determined. For 
Endothia parasitica the optimum appears to be at 27° C. or above, 
and the same may be true of the other species. 

At 40° C. or above no growth occurs. There is considerable evi- 
dence, however, that Endothia flu-em is less resistant to the higher 
temperatures than either E. 'parasitica or E. gyrosa. After several 
of the tests the flasks were kept at room temperature for some days. 
It was found that all developed normally except those which had 
been kept at 40° and 37.5° C. These developed more slowly than 
those which had been kept at lower temperatures. It was particu- 
larly noticeable also that E. parasitica and E. gyrosa developed prac- 
tically as well after being kept at 40° as at 37.5° C, while cultures 
of E. fluens which had been in 37.5° developed fairly well; but if 
kept at 40° for three days they entirely failed to develop. 

DISTRIBUTION OF THE SPECIES OF ENDOTHIA. 

During the past two years the writers have studied over 600 speci- 
mens of Endothia from various parts of the world. The greater 
number of these specimens have naturally come from the United 
States. The maps (figs. 1-4) show the known ranges of the various 
species in this country. Each dot on a map represents a locality 
from which the species has been collected. Frequently, of course, 
many specimens have come from a single locality ; hence the number 
of dots by no means represents the number of collections. 

In the case of Endothia parasitica, the dark portion represents 
the area over which the blight is practically continuous; that is, 
practically all the stands of chestnut are either diseased or dead. 
The dots represent known isolated infections and the solid line marks 
the botanical limit of the chestnut. 

Endothia gyrosa. is known only from the United States, but has a 
range in this country wider than that of any other species. As 
shown in figure 1. it has been found as far north as central Michigan, 
east to Connecticut, on the Pacific coast near San Francisco, and on 



ENDOTHIA PARASITICA AND EELATED SPECIES. 



49 



the Gulf of Mexico. There is, however, a very great difference in 
the abundance of this species at different points. In the southeastern 
United States — that is, the region south of central Indiana and 
southern Virginia and east of central Arkansas and Louisiana — this 
species occurs in great abundance wherever its hosts are found. 
Broken branch stubs and exposed roots of Liquidambar, Fagus, 
and Quercus are covered with fructifications of this fungus. This is 
especially true of roots exposed by erosion or excavation which have 
suffered mechanical injury through the tramping of men or cattle. 
Farther north in Maryland, New Jersey, and Connecticut only an 
occasional specimen is found. Three days' search in southern Con- 





h4y^^^ 








\ 




J 2 ^-— ^~2^«C7~' 


s\ — Or 

*\ jLj 






( (/v-J^ I 


J \ \* 








i\ 


Sjw 






K 






. \ 




V \r — /~— 




\ / • 


TW^* ^<rh 


\ P\\Jr--r---J 




*• »*A 

♦ \ 


• Y 









Fig. 1. — Outline map of the United States, showing the distribution of Endothia gyrosa. 

necticut, for example, yielded only two specimens, both on Liquidam- 
bar, showing pycnidia only. 

Endothia singularis is known at present only on oaks in the dry 
foothill regions of Colorado and New Mexico. Bethel, in a letter, 
states that it is very abundant in certain localities in Colorado. 

Endothia fluens has long been known to occur in both Europe and 
America. Recently, through the kindness of Dr. Y. Kozai, director 
of the Central Agricultural Experiment Station, Nishigahara, Tokio, 
Japan, the writers received four specimens of fungi on chestnut. 
One of these, collected by S. Tsuruta on October 14, 1914, in the 
Province of Totomi, was the pycnidial stage of an Endothia, which 
when cultured proved to be E.fluens. Ascospore material of this 
species has since been collected by Meyer at Nikko, Japan, on the 
bark of Pasania sp. 

43737°— Bull. 380—17 4 



50 



BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 



EndotMa fluens, while common to Europe, Asia, and America, has 
a much more limited range in the United States than E. gyrosa. It 
is fairly common on Castanea and Quercus from southern Pennsyl- 
vania and Ohio to northern Mississippi and Alabama. In south- 
eastern Pennsylvania it has been found so far only on roots of 
Quercus, and in northern Mississippi and Alabama only on Castanea 
dentata. 

EndotMa fluens mississippiensis was first sent to the writers from 
Corinth, Miss., by Mr. T. E. Snyder, of the Bureau of Entomology, 
and has since been collected in only four other localities, three near 
the northeastern corner of Mississippi and one in central Kentucky. 



? \ 










TCrn 




pV__^S^^-'y J } < \C 


/ ^w~ — ———J \ 




( Xs<C^-~^A^^ 








\-r^ 




i 




X%\ ^^N 




v^^^^j^ 







Fig. 2. — Outline map of the United States, showing the distribution of EndotMa fluens. 

As both EndotMa gyrosa and E. fluens were collected in this 
country nearly a century ago by Schweinitz, it seems altogether 
probable that they are indigenous species which may have already 
reached the limits of their natural ranges in this country. 

While the maps (figs. 1-4) do not give by any means every locality 
where Endothia is to be found and specimens are likely to be col- 
lected at many points outside the present known range, the writers 
feel justified in assuming that these maps represent the limits of 
the territory where Endothia gyrosa and E. fluens may commonly be 
found. This is especially true in the eastern portion, where the field 
has been rather thoroughly worked. It is unlikely, for instance, 
that E. fluens occurs abundantly in southern Alabama and Georgia, 
where E. gyrosa was found so commonly. Southeastern Pennsyl- 
vania must be somewhere near the northern limit for E. fluens, for 
the writers' four collections in that region are the result of six days' 



ENDOTHIA PARASITICA AND RELATED SPECIES. 



51 



search. At the northeastern limit of E. gyrosa, Clinton (15, p. 79) 
found only a single specimen after two years' search, and the writers 
have looked for it in all the other New England States without find- 
ing a single specimen. The report of E. gyrosa from Massachusetts 
by Hitchcock (42, p. 63) has already been shown to be a probable 
error in identification. 

FACTORS INFLUENCING DISTRIBUTION. 

HOST RELATIONS. 

Just what determines the present ranges of the species can not, of 
course, be positively decided, but some relation to certain external 
factors may be traced. Neither species has the same distribution as 




Fig. 3.— Outline map of the United States, showing the distribution of Endothia fluens 
mississippiensis and E. singularis. The dots indicate collections of E. fluens mississippi- 
ensis and crosses indicate collections of E. singularis. 

its hosts. Quercus and Fagus are both abundant farther north than 
Endothia gyrosa has yet been found, while Quercus is abundant 
north and south of the known range of E. fluens. It may be worthy 
of note, however, that E. gyrosa extends north as far as Liquidambar 
is found. Perhaps more significant is the relation of the range of 
E. -fluens to that of the chestnut. As will be seen from a comparison 
of the maps (figs. 2-4) , E. fluens is not found abundantly at any point 
outside the natural range of the chestnut. Especially interesting is 
the fact that the southeastern limits of E. -fluens and Castanea den- 
tata are practically coincident, for in this region Endothia. fluens 
was found only on Castanea, never on Quercus. This suggests the 
possibility that Castanea may be the original and favorite host of 
Endothia fluens. 



52 



BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 



SOIL CONDITIONS. 



Greater opportunity for infection seems to be an important factor 
in the greater abundance of Enclothia in the South. By far the most 
favorable places of infection, especially for EndotMa gyrosa, are 
bruised or broken but still living roots. Soil, cultural, and climatic 
conditions combine to make these many times more abundant in 
the Southern States than elsewhere. The more sandy and easily 
eroded soil, usually without turf, subject throughout the winter to 
the action of wind and rain, leaves innumerable oak roots exposed, 
which are readily injured by vehicles and the tramping of horses and 
cattle, leaving wounds suitable for the entrance of Endothia. In the 











\ 














-1 rJ 


^—-^J^, 



Pig. 4. — Map of the United States, showing the distribution of Endothia parasitica in 
December, 1915. The solid portion shows the area in which E. parasitica is generally 
present. The dots indicate scattered infections. The heavy line shows the limits of 
the range of Costarica dcntata. 

North, the more rocky soil, frequently covered with sod, protected 
through much of the winter by snow, makes exposed roots much less 
common, and the roots so exposed are rather less subject to mechani- 
cal injury. In the writer's experience the most favorable localities 
for collecting E. gyrosa, are the unfenced public squares of Southern 
towns, where partial grading, erosion, and constant traffic have left 
hundreds of oak roots exposed, and the pastures of southwestern In- 
diana, where the roots of Fagus are often found injured by cattle. 

COMPETITION AMONG FUNGI. 

The writers' extensive field studies and observations have con- 
vinced them that competition among fungi must be considered as a 



ENDOTHIA PARASITICA AND RELATED SPECIES. 53 

factor in determining their distribution. As already stated, while 
Endothia fluens occurs on Quercus, it has been found toward the 
southwestern limit of its range (northern Mississippi and Alabama) 
only on Castanea, and in Tennessee the writers have sixteen collec- 
tions of this species on Castanea and only three on Quercus. In 
this same region, E. gyrosa is everywhere abundant on Quercus. In 
numerous inoculations with E. gyrosa and E. fluens on oak it has 
been found that E. gyrosa is more generally successful than E. fluens. 
Moreover, E. gyrosa occurs abundantly on Liquidambar and Fagus 
in this region, thus providing more numerous sources of infection 
for this species than for E. fluens. It seems highly probable, there- 
fore, that E. gyrosa, with its greater affinity for oak and greater 
opportunity for infection, may occupy the available oak roots to 
the exclusion of E. fluens, even though climatic conditions are favor- 
able for the growth of the latter species. Castanea rarely serves as 
a host for E. gyrosa; consequently, on this host E. fluens meets with 
little competition and is very abundant. 

In the northeastern limit of its range, Endothia fluens has been 
found only on oak roots. Whether it grows naturally on chestnut 
in this region can not well be determined, since practically all the 
chestnut trees here are dead or badly diseased with E. parasitica. 
E. gyrosa is rare in this region, but E. fluens here evidently comes 
into competition with Valsa frustum-coni (Schw.) Curtis, which is 
common on exposed roots of various species of Quercus. 



Since none of the species of Endothia in America extends to the 
limits of its host species, climate probably has an important part in 
determining their present ranges. 

In this connection it is of interest to compare several life zone and 
climatic maps which have been published with the range maps of 
the various species of Endothia. The map entitled " Life zones of 
the United States," by C. Hart Merriam (50, pi. 14), is based largely 
on a study of animal life. Merriam deduces from his studies the 
conclusion that the northward distribution of animals and plants is 
determined by the total quantity of heat and their southern dis- 
tribution by the mean temperature of the hottest part of the year. 
The life zones which he outlines show, however, a striking relation 
with the known ranges of Endothia in America. With the exception 
of a single locality for Endothia gyrosa in Michigan, all the known 
localities for E. gyrosa and E. fluens fall within the Upper Austral 
and Lower Austral zones. All the known localities for E. fluens and 
all the region where E. gyrosa has been found abundantly fall within 
the humid divisions of these zones. The northeastern limits of the 
Upper Austral coincide very closely with those of E. gyrosa; its 



54 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

limits in Pennsylvania include the northern localities known for 
E. flu-ens, while the southern limits of this zone coincide closely with 
the southern limit of E. fiuens. 

The Livingstons (47) have published maps based on temperature 
summations and temperature efficiencies, as well as maps in which 
isoclimatic lines of temperature are combined with precipitation 
indices and evaporation indices for the mean frostless season. 

While no very definite relations between these maps and the ranges 
of Endothia can be traced it is noteworthy that the localities where 
Endothia gyrosa is known to be abundant are all south of or near 
the 600 line of temperature efficiency, and only one collection of 
E. gyrosa has been made north of the 400 line. E. singularls, on the 
other hand, has thus far been found only north of the 400 line. 

Zon's map (86) of vegetal regions of the United States is based on 
periods of growth and rest. The regions where Endothia gyrosa 
and E. fiuens are abundant are all south of the line which marks the 
northern limit of seven months' vegetation. In fact this coincides 
very closely with the northern limit of E. fiuens, and no specimen of 
E. gyrosa showing ascospores has been found farther north. 

The relations pointed out above strongly suggest the possibility of 
some causal connection between climatic conditions and the present 
ranges of Endothia species, but just what factors may limit the 
spread of the species is not yet determined. The temperature tests 
recorded on pages 45 to 48 throw little light on this problem, for the 
maximum and minimum temperatures are about the same in the vari- 
ous species. Endothia fluens seems to be less resistant to the effects of 
high temperature (40° C), but it is difficult to see that this fact alone 
has any direct bearing on the question of distribution. 

DISCOVERY OF ENDOTHIA PARASITICA IN CHINA. 

For eight years after its discovery in the New York Zoological 
Park in the summer of 1904, Endothia parasitica was known only 
from eastern North America. During this time two quite different 
opinions as to the origin of the fungus were advanced. Some in- 
vestigators maintained that E. parasitica was an indigenous fungus 
(15) ; others that it had been imported from some foreign coun- 
try, probably oriental (51, 52.) In the fall of 1912, however, pyc- 
nospore material was sent from Agassiz, B. C, by H. F. Giissow, 
Dominion Botanist of Canada. Cultures made from this material 
w T ere identical with E. parasitica, and a series of inoculations on 
Castanea dentata produced typical cankers. Later, a large quantity 
of material collected at Agassiz by Dr. James K. Weir was received, 
which included a few ascospores. These proved to be typical 
E. parasitica. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 55 

A brief description of the identification of other specimens of 
E. parasitica from Agassiz is given by Faull and Graham (29). 
These writers report that in the material sent them in the summer 
of 1913 there were no perithecia, but that the pycospores were typical 
E. parasitica and the characteristic mycelial fans were present in 
the bark. Cultures of the fungus proved it to be identical with 
E. parasitica. They also state (p. 203) that the chestnuts grown 
at Agassiz " are of oriental, European, and American origin. The 
stock was purchased from nursery firms located in New Jersey, 
Ohio, and California. One of these at least ' was a heavy importer 
of oriental trees and shrubs '." They suggest that it " is significant 
that a connection with the Orient exists." 

In support of this view, the statement of Mr. Sharpe, who had 
charge of planting the nut orchard at Agassiz, may be given. Dr. 
Weir visited Mr. Sharpe at Salmon Arm, B. C, and Mr. Sharpe 
stated definitely to him that he would be willing to furnish affidavit 
to the effect that in the main or entirely the chestnut trees in the 
nut orchard were originally imported from the Orient; in fact, a 
part of the trees, according to Mr. Sharpe, undoubtedly came from 
Japan or China and were shipped to Agassiz in the original wrap- 
pings, which consisted of the peculiar mats and casings of those 
countries. 

In a letter accompanying the specimens from British Columbia 
Giissow states that " these trees may be regarded as absolutely iso- 
lated. There is no other chestnut tree anywhere round it for 500 
miles and more." It seems highly probable therefore that E. para- 
sitica was carried to this locality on nursery stock, perhaps as sug- 
gested by Faull and Graham and by Weir by importation from the 
Orient. 

The following spring (1913) Mr. Frank N. Meyer, agricultural 
explorer, discovered this fungus in Chihli Province, China, under 
such conditions as could leave no doubt that it is indigenous there. 
The account of this discovery and its corroboration in this country 
was published by Fairchild (27), and also by the writers (76). 

As outlined by Fairchild (27), Meyer first found the diseased 
chestnuts near Santunying, a small town 1| days journey by cart from 
a railroad, northeast of Peking in Chihli Province, between Tsunhua- 
tcho and Yehol. 

A small specimen of diseased chestnut bark from this region was 
inclosed in a letter from Mr. Meyer which was received by Mr. Fair- 
child on June 28, 1913. From this specimen, which showed only 
pycnospores, cultures were obtained, which proved it to be true E. 
parasitica. On July 23 more Chinese specimens were received from 
the same locality, as well as from Scha Ho in the same Province. 
These included a large canker on a chestnut branch about 6 cm. in 



56 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

diameter, which agreed in every respect with cankers produred on 
varieties of Japanese chestnuts in this country (PL XXII). 

Other specimens in this collection showed well-developed perithecia 
and ascospores. The ascospore measurements made at the time, as 
well as the cultures of the Chinese fungus and the inoculation experi- 
ments on C. dentata, are described in the previous paper by the 
writers (76, p. 296). 

Shortly after this first series of inoculations was made subcul- 
tures of the Chinese material were sent to several investigators who 
had been studying the chestnut-bark disease, in order that the 
Endothia from China might be tested as soon as possible under 
American conditions by inoculations at various points throughout 
the known range of the disease. 

A series of inoculations was made by Prof. J. Franklin Collins at 
Martic Forge, Pa., on July 14, 1913, using American and grafted 
Paragon and grafted Japanese chestnut trees. Another series of 
inoculations, 56 in number, was made at the same locality Septem- 
ber 10, 1913, by Dr. Caroline Rumbold on grafted Paragon chest- 
nuts. Twenty inoculations were made on native chestnuts at Ander- 
son, Pa., October 2, 1913, by Dr. F. D. Heald and R. A. Studhalter. 
Inoculations with the Chinese Endothia were made at Leesburg, Va., 
on both Costarica dentata and C. fmmila by G. Flippo Gravatt and 
J. T. Rogers, August 16, 1913. 

All these investigators made duplicate inoculations with American 
material, and all agreed that the Chinese fungus was identical in its 
effects on the host with the American chestnut-blight fungus. Dur- 
ing the season of 1914 numerous inoculations with material from 
China were made by the writers at various points in New Hamp- 
shire, Massachusetts, Connecticut, New York, Delaware, and Mary- 
land, while others have been made in Rhode Island by Prof. Collins 
with the same results. 

ADDITIONAL CHINESE SPECIMENS. 

Since the publication of the previous paper (76) additional speci- 
mens of E. parasitica from China have been received from Meyer; 
one collected at Changli, Chihli Province, China, October 13, 1913, 
by Mrs. Mary S. Clemens ; a quantity of material collected by Meyer 
himself in the village of Tachingko, near Taianfu, Shantung, China, 
March 21, 1914; and another collected by him at Yatyeko, Shensi, 
China, September 2, 1914. A few cankers have also been sent by 
Meyer, collected by him at Shihbonshan, near Hangchow, Chekiang 
Province, China, June 26, 1915. The label on this specimen bears 
the further comment, " very destructive in this locality." Cultures 
have been made from all these specimens and have invariably proved 
to be identical with cultures of E. parasitica found in this country. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XXII. 




An Old Canker Caused by Endotkia parasitica on a Branch of Castanea 

mollissima. 

Collected by Frank N. Meyer, May 31, 1913, uear Santunying, Chihli Province, China. 



Bui. 380, U. S. Dept. of Agriculture. 



Plate XXIII. 





S*^4- 










^ 


-.. ^ 


ittMMfl^nHrfci r* " « *\* 


g^T^>; 






^£ 


.',j* ,— j. 


^L^r'f** X l Mki ^£ 






| ^y 




.■sjj 






... I,.*- 






»* life Sii 


i 


















ife- 




i ^, '- '■v'.-^KS 


.-tvk^.:^. 




■:£.. ^v.- 


, ; ■ ; 











Fig. 1.— Japanese Chestnut at Nikko, Japan, from Which the Chestnut 
Blight Fungus (Endothia parasitica) was Collected by F. N. Meyer, on 
September 17, 1 915. 




Fig. 2.— Two Branches of a Japanese Chestnut. The Larger (to the Left) 
Was Brought to This Country by F. N. Meyer, and from It Endothia 
parasitica Was Isolated. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 57 

As Tachingko is 300 miles south of Changli, where E. parasitica was 
first collected by Meyer, and Yatyeko is 500 miles west of Tachingko, 
it seems highly probable from the collections that E. parasitica is 
widely distributed in China (fig. 5). 

Meyer, writing from Hangchow, July 1, 1915, refers as follows to 
the condition of the chestnuts in that locality : 

Well, I have a few interesting discoveries to report. First, there are many 
specimens of Castanea mollissima scattered at the bases and on the lower 
slopes of the hills around here, and these chestnuts are seriously attacked 
by the bark fungus, and in my estimation are going to succumb to it these 
coming years. The chinquapins (Castanea spp. ), however, which are very 
abundant on the higher and more sterile hill slopes, seem to be immune ; 




Fig. 5. — Outline map of China and Japan, showing the localities in which Endotliia 
parasitica has been found. 

at least I did not see any evidences of damage or even of attacks. This 
brings another interesting point to my mind. I was told in Nanking that 
various missionaries at Ruling, the great summer resort in central China 
for missionaries, were cutting down their chestnuts, as the tops w T ere all 
dying, due to borers working underneath the bark. 

Meyer has since stated to the writers that he believes the de- 
struction of the chestnut at Ruling is due to Endothia parasitica 
rather than to borers. 

In the writers' earlier publication the following statement was 
made (76, p. 297) : 

The Chinese organism has thus been shown to be practically identical with 
the American in all its morphological and physiological characters and in 
the production of the typical chestnut blight and the pyenidial fructifications 



58 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

of the fungus. There is apparently but one other requirement that could be 
made according to the strictest pathological canons to perfect the proof in 
this case, and that is the production of typical ascospores of E. parasitica 
on the lesions produced by the inoculations. 

The last requirement has now been fulfilled. Specimens collected 
February 15, 1915, from inoculations made September 20, 1913, on 
chestnuts in Virginia, near Point of Rocks, Md., with Chinese ma- 
terial, show perithecial stromata with typical ascospores of E. 'par- 
asitica, thus completing the evidence. 

DISCOVERY OF ENDOTHIA PARASITICA IN JAPAN. 

More than two years after his original discovery of Endothia 
parasitica in China (June 3, 1913), Meyer also discovered the fungus 
in Japan. A brief account of his discovery has already been pub- 
lished by the writers (78). It may be sufficient here to state that fol- 
lowing the discovery of Endothia parasitica in China the writers 
endeavored by correspondence to obtain the fungus from Japan. 
While not successful in obtaining Endothia parasitica, the writers 
did receive several specimens of fungi, including species of Endothia 
on species of Castanea. These, together with several specimens of 
fungi found on chestnut nursery stock from Japan, make it clear 
that there are in that country several Pyrenomycetes other than 
Endothia parasitica more or less parasitic on Castanea. 

Meyer first discovered the chestnut-blight fungus in Japan at 
Nikko, September 17, 1915, on wild trees of Castanea crenata Sieb. 
and Zucc. A photograph of the trees from which he collected speci- 
mens of Endothia parasitica is shown in Plate XXIII, figure 1, and 
a branch from which the diseased material brought to the United 
Sates was taken is shown in Plate XXIII, figure 2. 

Shortly after Meyer's arrival in Washington in December, 1915, 
the specimens collected at Nikko were turned over to the writers for 
study. Examination at once showed cankers and mycelial fans 
typical of Endothia parasitica. The material also contained typical 
pycnospores and ascospores of the fungus. Cultures made from 
single ascospores on various culture media proved to be identical 
with those of Endothia parasitica found in this country and in China, 
thus establishing beyond question the identity of the fungus. 

Meyer's observations as to the resistance of the Japanese chestnuts 
to this disease are of great interest. He states that the trees vary 
considerably as regards their power of resistance, but that in general 
the Japanese chestnut is even more resistant to Endothia parasitica 
than is the Chinese chestnut (Castanea rnollissima) . 

As announced in the same publication (78), Endothia parasitica 
was collected by Dr. Gentaro Yamada at Morioka, northern Japan. 
These specimens, which show typical cankers as well as ascospores of 
the fungus, were received by the writers on January 8, 1916. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 59 

PRESENT DISTRIBUTION OF ENDOTHIA PARASITICA IN AMERICA. 

The present range of Endothia parasitica in America, as shown by 
the map (fig. 4), is probably merely the extent to which it has been 
able to spread in the time since it was first introduced. 

Whether Endothia parasitica was introduced into one locality or 
several is uncertain, but the studies of Heald (40, 41) and others have 
shown clearly that the spores of E. parasitica are carried by the wind, 
by insects and birds, and on nursery stock, which would account 
for its wide distribution and for its occurrence in isolated localities, 
long distances away from the main body of the disease. It also makes 
it seem probable that the fungus will continue to spread with some 
rapidity. 

Certainly, there is no evidence that any factor, climatic or other- 
wise, is likely to prevent the spread of this fungus into the large area 
of chestnut south of its present range. On the contrary, the duplicate 
inoculations made by the writers show clearly that the fungus grows 
more rapidly at the southern limit of its present range than farther 
north, where it is much more common. The longer growing season 
in the South is also no doubt an important factor. 

In this connection, it may be noted that Koppen (46), in his map 
of the vegetation regions of the earth, places the portion of China 
where Endothia parasitica has been found indigenous in the same 
climatic region as that portion of the United States where it is now 
doing such destructive work. He designates this region as the 
" Hickory " division of the mesotherms. 

HOST RELATIONS OF THE SPECIES OF ENDOTHIA. 

ENDOTHIA GYROSA. 

Endothia gyrosa occurs commonly on Liquidambar, Fagus. and 
Quercus, occasionally on Castanea, and has been found on Vitis in 
Alabama, but the writers were unable to obtain fresh material from 
this host. 

While Fagus and Quercus are, of course, closely related, it seems 
remarkable that a fungus should be abundant on hosts so different 
as Liquidambar and Quercus, yet so rare on any other host as to be 
only once reported. It seemed possible, indeed, that the fungus on 
Liquidambar. while morphologically and culturally identical with 
that on the various other hosts, might prove to be physiologically dif- 
ferent. In order to obtain more definite information on this point, 
several series of cross inoculations were made. 

It had been observed that Endothia gyrosa was found most fre- 
quently on the cut or broken ends of branches or on exposed, bruised, 
or broken roots. In making inoculations, therefore, a small branch, 



60 



BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 



1 inch or less in diameter, was cut off about 6 inches from the 
main trunk. Mycelium from corn meal in flasks was placed on the 
cut end of the stub and covered with wet cotton, over which oiled 
paper was tied. In about two weeks the paper and cotton were re- 
moved. In all cases, branches similar to those inoculated were cut 
as checks. 

Tablk III. — Inoculations with Endothia gyrosa. 



Source of fungus and 
date. 



Host inocu- 
lated. 



Number 
of inocu- 
lations. 



Number 
success- 
ful. 



Remarks. 



Fagus: 

May 8, 1913 . . , 
May 29, 1913 . 

Sept. 15, 1913. 

Do 



Apr. 2, 1914 . 
Do 

Do 



May 23, 1914 . 

Do 

Do 

Do 

Quercus: 

May 29, 1913. 

Do 



Sept. 15, 1913. 
Do 



Apr. 2, 1914 . 

Do 

Do 



May 23, 1914 . 



Do 

Do 

Do 

Castanea: 

May 29, 1913 . 
Do 



Apr. 2, 1914 . 
Do 



Do. 



May 23, 1914 . 



Do 

Do 

Liquidambar: 

May 29, 1913 . . 
Do 

Sept. 15, 1913. 



Do. 



Do 

Apr. 2, 1914 . , 

Do 

Do 

May 23, 1914 . 

Do 

Do 

Do 



Castanea . 
Fagus — 



Liquidambar 
Quercus 



Fagus — 
Quercus.. 
Castanea . 



....do 

Liquidambar 

Quercus x 

Fagus 



....do 

Liquidambar 



....do... 
Castanea . 



Fagus — 
Quercus l 
Castanea . 

....do... 



Liquidambar 

Quercus ' 

Fagus 



....do 

Liquidambar 



Fagus... 
Quercus ' 



Castanea . 



.do. 



Liquidambar 
Quercus > 



Fagus 

Liquidambar 
Fagus 



Castanea . 



Quercus 

Fagus 

Quercus ' 

Castanea 

do 

Liquidambar 

Quercus ' 

Fagus 



Pycnospores first observed on Oct. 16. 

Pycnospores first observed on Aug. 29 for 
two and on Oct. 10 for the third. 

No growth until the spring of 1914; pyc- 
nidia scattered and small on Oct. 13. 

No growth until spring; well developed on 
Oct. 13, 1914. 



Pycnidial stromata well developed on Oct. 
13, 1914. 
Do. 



Do. 

Pycnospores first observed on Aug. 29, 1913. 
Very slight indications of growth on Aug. 

29, 1913; a few pycnidia with spores on 

Oct. 16. 

Large well-developed pycnidia on Oct. 13, 
1914. 



Large abundant pycnidial stromata on Oct. 
13, 1914. 

Abundant well-developed pycnidial stro- 
mata on Oct. 13, 1914. 



Pycnospores first observed on Aug. 29, 1913. 
Slight indications of pycnidial formation on 

Aug. 29, 1913; pycnospores on all on Nov. 

17, 1913. 

Large well-developed pycnidial stromata 

on Oct. 13, 1914. 
Scattered, fairlv well-developed pycnidia 

on Oct. 13, 1914. 
Abundant well-developed pycnidia on Oct. 

13, 1914. 



Pycnospores first observed on Aug. 29. 

No evidence of growth until the spring of 
1914; pycnidia few T and small on Oct. 13. 

No growth until the spring of 1914; pyc- 
nidia small on Oct. 13. 



Abundant pycnidia on Oct. 13, 1914. 



i The species used in this case was Quercus prinus, which proved to be an exceedingly unfavorable host 
for Endothia gyrosa. 



ENDOTHIA PARASITICA AND RELATED SPECIES. l 61 

Inoculations with Endothia gyrosa were also made on numerous 
hosts from which it had never been reported. Six or more inocu- 
lations were made on each host, in the manner described above, ex- 
cept that a part of each series was left unwrapped. The following 
inoculations showed no growth whatever: Those made in Virginia, 
April 4, 1914, on Cornus florida, Fraxinus americana, Juglans cinerea, 
Ilex opaca, Sassafras variifolium; in Maryland, April 17 and 22, 
1914, on Carya glabra, Comus florida, Liriodendron tulipifera, Nyssa 
sylvatica, Sassafras variifolium, and Quereus alba; and in New 
York, July 11, 1914, on Betula alba, Primus serotina, Populus trem- 
uloides, Rhus glabra, Salix sp., and Sassafras variifolium. On Acer 
pennsylvanicum and Carya two out of the six inoculations developed 
a few stromata. These were found only on the tissue injured by 
the cut and there was no evidence of parasitism. 

On Castanea, Fagus, Quereus, and Liquidambar, however, a branch 
inoculated as described above dies back rather faster than the checks. 
This would indicate, as suggested by Clinton (18, p. 419), that 
E. gyrosa is a weak parasite ; that is, that it is able to invade injured 
and dying tissue. 

It is evident from Table III that Endothia gyrosa coming from 
any of the four hosts named will, under favorable circumstances, 
grow on any of the others. Several other interesting facts are 
brought out by the table. Inoculations made with material from 
Liquidambar grew in general more rapidly on Liquidambar than 
on any of the other hosts. In many cases, material from Liquidam- 
bar failed to grow on Castanea, Fagus, and Quereus, and even when 
inoculations were successful growth was somewhat slower and pyc- 
nidial production less abundant. 

On the other hand, inoculations from Fagus, Quereus, and 
Castanea usually grew less rapidly on Liquidambar than on any 
of the other three hosts. This is, of course, what would be expected 
from the systematic relationships of the host species, and while the 
inoculations made are too few to permit any definite conclusions 
they are nevertheless suggestive. As shown by Table III, Quereus 
prinus proved a very unfavorable host for Endothia gyrosa. 

In all cases inoculations made in the fall (Sept. 15) failed 
to show any growth until the following spring. This corresponds 
with the results in inoculations of Endothia parasitica, but it is, of 
course, impossible to determine whether this failure to grow is due 
to the dormant condition of the host or to unfavorable weather con- 
ditions. Perhaps correlated with the results just noted are the 
unusually poor results obtained from inoculations made in the early 
spring. It will be noted that inoculations made on April 2, 1914, 
were in general much less successful than those made on May 23, 
1914, in exactly the same locality and in many cases on the same 
hosts. 



62 



BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 



ENDOTHIA SINGULARIS. 

The material of Endothia singularis distributed by Sydow as Calo- 
pactis singularis was on Quercus gambellii Nutt. The writers have 
seen abundant material on this species as well as specimens on Q. 
utahensis (A. DC.) Rydb., Q. leptophylla Rydb., and Q. nitescens 
Rydb. Specimens on the latter two hosts were sent by Bethel, who, 
in a letter, reports finding this species also on Q. pungens Liehm. 

All of these species except Quercus leptophylla are chaparral- 
forming shrubs growing at an elevation of 4,000 feet or more. 
There is at present no evidence that the fungus is parasitic on any 
of the species. 

Inoculations with the mycelium of Endothia singularis were made 
on Fagus and on Quercus alba, Q. velutina, Q. rubra, and Q. palustris, 
as well as on Q. ilicifolia on Overlook Mountain in the Catskills. 
No growth has, however, been noted in any case. 

ENDOTHIA FLUENS. 

When these investigations were commenced, the writers thought 
that the Endothia found in Europe might be the same as Endothia 
parasitica found in America. Inoculations were accordingly made 
in Maryland during October, 1912, with cultures from material col- 
lected on the chestnut by the senior writer at Stresa, Italy, and 
Etrembieres, Switzerland, using material of E. fluens sent by P. J. 
Anderson from Pennsylvania ; also material of that species and of 
E. parasitica collected in Virginia as checks. In this case, as in all 
others where no special mention is made of the method, inoculations 
were made by cutting through the bark to the wood with a sharp 
knife. The inoculating material was then inserted with a freshly cut 
twig and the wound tied up either with cord or rubber bands. If 
cord was used it was cut away within two to four weeks. The rub- 
ber bands became loosened by exposure to the weather within about 
the same time. 

Inoculations were made with all the above material on sprouts of 
Castanea dentata and Quercus prinus. The results are summarized 
in Table IV. 

Table IV. — Inoculations of Endothia in Maryland in October, 1912. 



Fungus. 



Host inoculated. 



Number 
of inocu- 
lations. 



Number 
showing 
growth. 



Endothia parasitica. 

Do 

E. fluens: 

European 

American 

Do 



Castanea dentata. 
Quercus prinus. . . 

Castanea dentata. 

do 

Quercus prinus 



•28 


14 
L'3 
9 



ENDOTHIA PARASITICA AND RELATED SPECIES. 63 

The inoculations were examined every 10 days until December 1 
and monthly thereafter throughout the winter. There was no per- 
ceptible growth until the last of April, when several of the inocula- 
tions of Endothia parasitica showed slight sunken areas. By May 
20 all inoculations checked as showing growth (last column of table) 
showed the slight yellowish elevations of the bark which indicate 
the beginnings of pycnidia. On August 30 all the inoculations of 
E. parasitica checked as showing growth had spread rapidly and 
attacked the living tissues of the host, producing typical cankers with 
mycelial fans and abundant pycnidia. 

No signs of growth were noted in the inoculations of Endothia 
fiuens until about the middle of May, 1913, when most of them 
showed signs of pycnidium formation. By August 30 all those 
marked as showing growth had produced characteristic pycnidia 
with spores, which when cultured proved to be typical E. fiuens. In 
no case, however, did this fungus spread for any appreciable distance 
beyond the injured portion or show signs of active parasitism. These 
results agree with those given by Anderson and Anderson (2, p. 206) 
with American material of E. fiuens, and have since been fully con- 
firmed by further observation. 

During the summer of 1914 about 1,100 inoculations of Endothia 
fiuens from both European and American sources and of E. fiuens 
mississippiensis were made on Castanea sprouts. In no case was 
there any evidence of active parasitism, as in E. parasitica. 

Although Endothia fiuens has been found in Europe on a con- 
siderable number of deciduous host plants (as recorded on p. 18), 
the writers have thus far failed to find it in this country on any 
except Castanea and Quercus. It seemed possible that the European 
strain of the fungus might be somewhat more plurivorous 1 in its 
habits than the American. In order to throw some light on this 
point, the following inoculations were made : 

On March 31, 1914, 10 inoculations were made, half of European and half 
of American material, at Francis, Md., on the following hosts: Alnus rugosa, 
Betula nigra, Carpinus caroliniana, Carya glabra, Fagus grandifolia, Lirio- 
dendron tulipifera, and Liquidambar styraciflua. Pycnidia appeared only on 
Carya glabra and Carpinus caroliniana. Of the inoculations which actually 
produced pycnidia, four on Carpinus and three on Carya, one of each was the 
European strain. 

On April 22 inoculations were made with American material of E. fiuens at 
Kensington, Md., on Acer rubrum, Carya glabra, Cornus florida, Fagus grandi- 
folia, Prunus serotina, Quercus prinus, Sassafras variifolium, Vaccinium sp., 

1 This term is proposed to apply to fungi occurring on two or more hosts or substrata 
and may be applied to all fungi except true parasites. It is derived from plus (plur-), 
more, and vorare, to devour. Compare omnivorous already in use for fungi. 

The term pleioxonous might be derived from De Bary's proposed word pleioxony and 
applied to true parasites having the power to invade more than one species of host plant, 
and the term plurivorous restricted to nonparasitic organisms. 



64 



BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 



and Titis sp. Of these, Acer rubrum and Carya glabra gave numerous small 
pycnidia. 

On July 10 the following hosts were inoculated at Woodstock, N. Y., with 
JJ. flu ens from Europe: Acer rubrum, A. pewnsylvanicum, Carya ovata, Corylus 
americana, Fraxinus americana, Hamamelis virginiana, Kalmia latifolia, Popu- 
lus grandidentata, Prunus serotina, Rhus glabra, Salix sp., Sassafras variifo- 
liion, and Syringa vulgaris. Each host was inoculated in six or seven places, 
hut all failed to develop except two inoculations on Acer pennsylvanicum and 
one on Corylus americana. 

The results cited above are so largely negative that they prove very 
little except that the European strain shows no special affinitj' for 
these hosts in America. 

ENDOTHIA FLUENS MISSISSIPPIENSIS. 

Only five collections of Endothia fiuens mississippiensis have thus 
far been made, three on Castanea dentata and two on Quercus sp. 
From the results of the inoculations its host relations appear very 
similar to those of E. -fiuens. The results are; shown in Table V. 

Table V. — Inoculations with Endothia fiuens mississippiensis on Castanea and 

Quercus. 



Source of culture. 


Host inoculated. 


Date. 


Number 
of inocu- 
lations. 


Number 
showing 
pycnidia. 






Jan. 20,1912 
May 8, 1913 
.....do... 


8 
4 
4 
9 
12 
12 


8 


Do 


do 


4 


Do 


do 


4 


Do 




do 


7 


Do 




Apr. 18,1914 
do. 


10 




do 


10 









The inoculations of January 20, 1912, showed no signs of growth 
until early in May, when the first signs of pyenidium formation were - 
observed. The inoculations with Endothia fiuens mississippiensis 
made May 8, 1913, showed within three weeks discolored areas near 
the cut which were larger than those about the check cuts. On July 
25, 1913, all of the inoculations of E. fiuens mississippiensis marked 
" successful " showed the beginnings of pyenidium formation. By 
August 30, 1913, they were producing pyenospores, which when cul- 
tured proved to be E. fiuens mississippiensis. 

Inoculations were made in April, 1914, for the purpose of com- 
paring the material collected on oak with that collected on chest- 
nut. No difference was detected, and there was no indication of active 
parasitism. This form behaved in this respect exactly as did the E. 
fiuens from Virginia both on Castanea dentata and Quercus prinus. 

A series of inoculations parallel to that made with E. fiuens was 
made with E. fiuens mississippiensis. The same hosts were used, 
and in most cases the dates and places of the inoculation were the 
same. The results of all that showed any growth are given in 
Table VI. 



ENDOTHIA PABASITICA AND RELATED SPECIES. 



65 



Table VI. — Inoculations with Endothia fluens mississippiensis on Acer and 

Carya. 



Location. 


Host. 


Number 
of inocu- 
lations. 


Number 
showing 
pycnidia. 


Woodstock, N. Y 




6 
6 
6 

1 
2 




Do „ 




2 


Francis, Md 




1 


Kensington, Md 




1 


Do 




o 









As in Endothia fluens the growth was confined to the injured tis- 
sues, and there was no evidence of parasitism. 

ENDOTHIA TROPICALIS. 

The material of Endothia tropicalis from which the writers se- 
cured their cultures, was collected by T. Petch in Ceylon. As the 
species of Endothia in the Northern Hemisphere are chiefly on 
members of the Fagacese, Petch's statements with regard to hosts 
are of considerable interest. In a letter of March 6, 1914, he writes: 

We have no Fagacere native in the island. We have introduced various 
species of Quercus and Castanea, but subsequent to Thwaite's discovery of 
this fungus. I do not think there can be any doubt that the fungus is native 
to Ceylon * * * 

Of the specinients now sent * * * those in the packet * * * are 
from a tree which was producing shoots from the base. This tree is Elaeocar- 
pus glanduiifcr Mast. From the bark and habit, I believe that all my " finds " 
of Endothia have been on this species. 

In the accounts of the American chestnut disease, I notice that several 
authors speak of " cankers," and give their rate of growth. I never see 
"cankers" (Krebs) on the Ceylon trees. The bark appears to die regu- 
larly and smoothly from above downward, and is quite unbroken except for 
the minute cracks through which the stromata emerge. 

Inoculations. — As already noted, ascospores of Endothia tropi- 
calis resemble those of E. parasitica even more closely than do those 
of E. fluens. This fact, together with its similarity on culture media 
and its oriental origin, led the writers to fear possible parasitic 
tendencies. 

Inoculation experiments were accordingly made only on the chest- 
nut and under carefully guarded conditions. In all, about 30 
inoculations were made on 2-inch chestnut sprouts, using the methods 
described for other species. 

Of 25 inoculations made in May and June, practically all had de- 
veloped a few pycnidial stromata by October 20. These stromata 
were a somewhat brighter orange than those of E. fluens or E. fluens 
mississippiensis, and the spores when cultured produced typical E. 
tropicalis. In no case, however, was there any evidence of parasitism. 

43737°— Bull. 3S0— 17 5 



66 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

ENDOTHIA PARASITICA ON HOSTS OTHER THAN CASTANEA. 

The first collection of Endothia parasitica on a host other than 
Castanea of which the writers have any knowledge is that made by 
J. Franklin Collins at Martic Forge, Pa., June 30, 1909. As an- 
nounced by Dr. Metcalf at the Boston (December, 1909) meeting 
of the American Phytopathological Society, the specimen consisted 
of a small dead branch of Quercus velutina with several spore 
tendrils typical of E. parasitica. This material, which consisted of 
a terminal branch with leaves still retained, was at once sent to the 
laboratory at Washington, and cultures obtained from it were sub- 
sequently used in making numerous inoculations on Castanea dentata 
on Long Island, N. Y., in July, 1909. On November 17 of the same 
year, Metcalf reported that the inoculations were entirely successful 
and had produced typical lesions, thus establishing without question 
the identity of the fungus. 

Fulton (37, p. 53) reports E. parasitica on the dead bark of Quer- 
cus alba and Quercus velutina, but found no evidence that the fungus 
produces in any sense a disease of such trees. Clinton (18, p. 428) 
mentions cultures from three different species of Quercus and (p. 
376) reports specimens on Quercus alba, Q. rubra, and Q. velutina. 

Anderson and Babcock, as quoted by Anderson and Rankin (6, p. 
564), found Endothia parasitica on Quercus velutina, Q. alba, Q. 
prinus, Rhus typhina, Acer rubrum, and Gary a ovata, but it seemed 
parasitic only on Quercus alba. They made inoculations with mate- 
rials isolated from Castanea on Quercus prinus, Q. velutina, Q. alba, 
Q. coccinea, Rhus typhina, Acer rubrum, Liriodendrontulipij 'era, and 
Carya ovata. Two trees of Rhus were girdled and killed by the 
growth of the fungus. On Quercus alba the fungus seemed slightly 
parasitic, but none of the trees were killed. The fungus grew and 
produced spore horns on the wounded tissue near the point of inocu- 
lation on all the hosts except Acer and Liriodendron. 

Rankin (62, p. 238) also made inoculations with Endothia para- 
sitica from Castanea on Quercus prinus, Q. rubra, Q. alba, and Q. 
coccinea. He found that the mycelium advanced into the living 
tissues for a short distance in a few cases, but that in no case were 
typical cankers formed. Pycnidia were produced abundantly on the 
injured tissues of all the hosts. 

During the course of this work only four specimens of Endothia 
parasitica on hosts other than Castanea have come to the writers. 
One was on chestnut oak (Quercus prinus) collected by F. W. Besley, 
at Towson, Md., December 26, 1911; one from Quercus velutina, at 
Germantown, Pa., as well as one from white oak (Quercus alba), at 
Kennett Square, Pa., were collected by S. B. Detwiler; and one 
from dead maple, Acer sp., at Florence, Mass., by Roy G. Pierce. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 67 

The specimen collected by Besley on Quercus prinus showed the fan- 
shaped mats of mycelium typical of E. parasitica on Castanea spe- 
cies. The fungus had apparently girdled the tree. The specimen on 
Quercus alba, collected by Detwiler, was similar to one on Quercus 
prinus in appearance and came from a dead tree which had appar- 
ently been killed by the growth of the fungus. The specimens on 
Acer sp. and on Quercus alba were received in the spring of 1914, 
and cultures isolated from them were used in making inoculations 
for the purpose of determining whether the fungus had either lost 
or gained in virulence by passing through other hosts. 

INOCULATION EXPERIMENTS. 

The cultures secured from Acer and Quercus, together with one 
made from Castanea at about the same time, were inoculated into 
three separate sprouts of Acer rubrum, Castanea dentata, and Quer- 
cus prinus. The sprouts chosen were of nearly the same size, 2 
inches in diameter, and similarly situated, and each was inoculated 
in five places, with two check cuts above. The inoculations were 
made the usual way on March 31, 1914, and were examined at least 
once a month during the summer. 

None of the inoculations on Quercus produced any growth what- 
ever. On Acer the inoculations with the culture from Quercus all 
failed to develop; one of the inoculations with the culture from 
Acer showed a few pycnidia, while four of the inoculations with 
material from the chestnut developed a few pycnidia. On Castanea 
the three series of inoculations were almost identical, every inocula- 
tion producing a typical canker. 

Of course, these inoculations are too few to be conclusive, but it 
is evident that there was no decrease in virulence on the chestnut 
in passing through Acer or Quercus and that no particular affinity 
for either Acer or Quercus was gained. On the maple, in fact, the 
culture direct from chestnut produced the most growth. 

In addition to those listed above, numerous inoculations were made 
in order to determine whether Endothia parasitica had any parasitic 
tendencies on other deciduous hosts. 

These inoculations were all made during the spring of 1914 by 
the usual method of cutting well through the bark and inserting 
mycelium and spores from a pure culture, usually on corn meal. 
The wounds were then wet, some bound with wet cotton, others with 
paraffin paper, and about half were left unwrapped. 

Seven or more inoculations were made on April 4 in Maryland on 
Alnus rugosa, Betula nigra, Carpinus caroliniana, Fagus grandifolia, 
Kalmia latifolia, Liriodendron tulipifera, and Liquidambar styraci- 
fiua, none of which developed. Inoculations were also made on April 



68 



BULLETIN 3S0, U. S. DEPARTMENT OF AGRICULTURE. 



22 in this locality on Acer rubrum, Carya glabra., Cornus forida, 
Fagus grandifolia, Liriodendron tulipifera, Quercus primes, Sas- 
safras variifolium, Vaccinium sp., and Vitis sp. without success. 
On April 18, the following hosts were inoculated in Virginia : Acer 
rubrum, Betula nigra, Benzoin aestivale, Carpinus caroliniana, Carya 
glabra, Cornus florida, Fagus grandifolia, Liriodendron tulipifera., 
Primus serotina, Quercus alba, Ulmus americana, and Vitis sp. 
Each host was inoculated in from four to six places. Of these, 
pyenidia were produced only on Acer rubrum, Carpinus, and Lirio- 
dendron. A similar series was made on the same hosts in the same 
place on May 27. Inoculations on one tree of Quercus alba showed 
undoubted evidence of parasitism and is described below. 

On July 9 and 11 from five to fourteen inoculations were made 
on each of the following hosts at Woodstock, N. Y. : Acer rubrum, 
Betula alba, Carya ovata, Fagus grandifolia, Frascinus americana, 
Hamamelis virginiana, Juglans cinerea, Kalmia latifolia, Nyssa syl- 
vatica, Ostrya virginiana, Populus grandidentata, Prunus serotina, 
Rhus typhina, Quercus rubra, Salix sp., Sambucus canadensis, and 
Sassafras variifolium. Pyenidia appeared on Acer rubrum and 
Ostrya only. The fungus made considerable growth on two plants 
of Rhus typhina, partly girdling branches one-half inch in diameter 
and producing distinct fans. The fans were, however, much smaller 
than those usually found in Castanea. Inoculations were made at 
Avon, Conn., July 15, on Acer saccharum, Betula alba, Carya glabra, 
Cornus florida, and Ostrya virginiana. Pyenidia developed only 
on Ostrya. The successful inoculations with Endothia parasitica 
are shown in Table VII. 



Table VII.- 



-Successful inocttlations in 191% with Endothia parasitica on hosts 
other than Castanea. 



Locality. 



Date. 



Host. 



Number 
of inocu- 
lations. 



Number 
success- 
ful.! 



Virginia 

Do 

Do 

Do 

New York... 
Do 

Connecticut.. 



Apr. 18 

..do 

...do 

May 27 
July 11 

..do 

July 15 



Acer rubrum 

Carpinus caroliniana . . . 
Liriodendron tulipifera . 

Quercus alba 

Acer pennsylvanicum. . 
Ostrya virginiana 

do 



1 Inoculations producing pyenidia are classed as successful. 

It must be noted that while pyenidia were produced in the cases 
listed as successful, there was no indication of parasitism, nor did 
the growth extend beyond the tissue injured by the cut except in 
Quercus and Rhus. 

Out of about 400 inoculations with Endothia parasitica on hosts 
other than Castanea, about TO of which were made on different 



I 



ENDOTHIA PARASITICA AND RELATED SPECIES. 69 

species of Quercus, chiefly Q. prinus and Q. alba*, only one case has 
been noted in which the fungus assumed a typically parasitic role. 
The data in this case may be summed up as follows : Four inocula- 
tions were made May 27, 1914, on a small tree of Qmrcus alba. This 
tree was suppressed, and although when cut down it showed about 
30 annual rings it was only 16 feet high and about 2 inches in diam- 
eter. It was in a moist, shady locality close beside a stream, and in 
spite of its small size was apparently healthy. The inoculations 
were made in the usual way from a culture of E. parasitica on corn 
meal. On August 1 it was noted that all four inoculations were pro- 
ducing pycnidia, and in at least one case typical fans had been 
developed. On October 15 all four cankers had more than half 
girdled the seedling. No observations were made during the winter, 
but at the time the leaves had reached half the normal size, in the 
spring of 1915, the tree was completely girdled. On July 1 this tree 
presented an appearance closely similar to that of a small chestnut 
tree girdled by Endothla parasitica. All the leaves above the point 
of inoculation were dead and remained attached to the branches. 
Below the girdled portion, water sprouts had developed, as has been 
frequently described for chestnut trees affected with E. parasitica. 
Cultures made from this tree showed the fungus to be typical of 
E. parasitica. Whether this case of parasitism was due to unusual 
virulence on the part of the fungus or to unusual susceptibility on 
the part of the host is, of course, merely a matter of conjecture ; the 
latter alternative seems, however, somewhat more probable, as other 
inoculations with this strain of the fungus on Q. prinus and Q. alba 
failed to show similar results. 

In addition to the above, a somewhat similar observation has been 
made by the writers near Amherst, Mass. In connection with other 
work, a sprout of Quercus prinus about an inch in diameter was 
inoculated with Endothla gyrosa on July 15, 1911. When this inocu- 
lation was made the tree was partly (about one-fourth) girdled. 
E. gyrosa developed normally and by October 1, 1914, had produced 
several pycnidial stromata. No change was apparent when the inocu- 
lations were examined in May, 1915. 

E. parasitica was abundant in the region, however, and apparently 
gained entrance through the cuts originally made, for when the plat 
was next visited, August IT, 1915, the sprout appeared quite dead, 
though still retaining its full-sized dead leaves. Further examina- 
tion showed numerous pycnidia of E. parasitica in addition to those 
of E. gyrosa near the region of the original inoculation. The pycnidia 
of E. parasitica were on all sides of the stem, while those of E. gyrosa 
were confined to the portion above the cuts made in inoculating. The 
mycelial fans typical of E. parasitica were abundant also. These 



70 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

observations leave no doubt that the tree was girdled and killed by 
E. parasitica, 

Endothia parasitica in exceptional cases undoubtedly attacks other 
hosts than Castanea, producing cankers and sometimes causing the 
death of the host. The results of the inoculations just recorded 
appear to indicate that some unusual conditions of host or parasite 
must obtain in such cases. Whether such a combination of conditions 
or factors will ever become sufficiently frequent to lead to serious 
destruction of Quercus or other forest trees remains to be determined. 

ENDOTHIA PARASITICA ON CASTANEA SPP. 

Although found occasionally on species of other genera, Endothia 
parasitica is dangerously pathogenic only on members of the genus 
Castanea. The parasitism of this fungus on the American chestnut 
{Castanea dentata) was first proved by Murrill (57) and has since 
been demonstrated by numerous investigators. 

When Endothia parasitica was discovered in the United States it 
was considered by some investigators to be a native fungus which 
had suddenly become parasitic, and various theories were advanced 
to account for the supposed unusual susceptibility of the host. As 
enumerated by Clinton (18, p. 391), the factors suggested include 
winter injury, drought injury, fire injury, weakened condition due 
to continued coppicing, and reduced amounts of tannic acid due 
perhaps to weather conditions. 

Continued study by many investigators in different localities has, 
however, fully confirmed the observation originally made by Met- 
calf and Collins in 1910 (53) that " a debilitated tree is no more 
subject to attack than a healthy one " and that Endothia parasitica 
is actively parasitic on the healthiest specimen of Castanea dentata 
in case there is opportunity for wound infection. The writers have 
personally made over 1,200 inoculations of E. parasitica on Castanea 
dentata without finding a single individual that showed any re- 
sistance. 

CASTANEA ON LIMESTONE SOILS. 

Not only are all trees susceptible, but so far as is known no con- 
dition of soil, altitude, or moisture renders them more resistant to 
the disease. The idea has been held by some writers that chestnuts 
grown on limestone soils were immune to the disease, and the plant- 
ing of chestnut orchards on such soils was advocated. This view 
is held by Gulliver (38, p. 53), who sums up his observations in two 
regions in Pennsylvania as follows: 

In every series of tracts taken from limestone to overlying shale soils, the 
percentage of blight is least at a comparatively short distance * * * from 
the edge of the limestone. Tracts on soils derived from limestone which 
show the highest percentage of blight seem to be those where the soil has 



ENDOTHIA PARASITICA AND RELATED SPECIES. 71 

become acid from underground drainage. Chestnut trees on soils derived 
from other alkaline rocks show less blight than is found in the trees on shale 
soils with limestone underneath. 

On the other hand, Detwiler (24, p. 67) reports observations in 
the Lizard Creek valley which seem to show that these relations do 
not always occur. He says — 

A belt of limestone borders Lizard Creek valley on the south, and the per 
cent of infection is as high in that region as elsewhere. Infection centers 
have been found near limestone quarries, where the roots of the chestnut pene- 
trated to bedrock. 

Actual proof or disproof of the truth of this idea was peculiarly 
difficult, since chestnut is but rarely found growing naturally on 
calcareous soils. During the summer of 1914, however, a careful 
study of the chestnut on certain portions of limestone areas in west- 
ern Maryland and western Connecticut was made. These localities 
were chosen because they were convenient in connection with other 
work, the blight had been present for several years in both States, 
and thorough State geological surveys made the location of the lime- 
stone areas very eas}^. The two States also are sufficiently far apart 
to eliminate sources of error that might arise from local weather 
conditions. 

In western Connecticut chestnut was abundant on glacial till over 
the Stockbridge limestone of this region. Chestnut was also grow- 
ing directly over limestone at various points near Danbury, Twin 
Lakes, Chapinville, and Lakeville. Several localities near the latter 
place were kindly pointed out by Dr. George E. Nichols. Near Dan- 
bury every tree examined showed the blight in a more or less ad- 
vanced stage, while near the other towns, all in the northwest corner 
of the State, nearly 50 per cent of the trees were blighted. About 
30 inoculations were made on sprouts in this region, and all 
except two developed cankers quite as rapidly as did check inocula- 
tions made on the trap ridge west of Hartford. 

Chestnut is very rare on the Shenandoah limestone in the Hagers- 
town and Frederick valleys of western Maryland. A number of 
chestnut trees were, however, located growing on limestone soil near 
Frederick Junction and Adamstown in the Frederick valley. The 
disease was already established west of Adamstown, where 20 per 
cent of the chestnuts were either diseased or dead. Twenty-two in- 
oculations were made on nine chestnut sprouts in these two regions, 
and all developed typical cankers quite as rapidly as the checks made 
in similar sprouts growing over Baltimore gneiss 50 miles east. 

RECESSION OF THE CHESTNUT IN THE SOUTHERN STATES. 

While it has been definitely proved that Endothhi 'parasitica is 
pathogenic on healthy chestnut trees, one of the points brought for- 



72 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

ward by the advocates of the " weakened host " theory seems to be 
fully established; that is, that the chestnut trees have suffered se- 
verely in the southern Appalachian regions previous to the present 
epidemic, in some cases being practically exterminated, so that the 
range is now considerably less than formerly. The evidence on this 
point has been summarized by Clinton (18, pp. 408-413). Various 
writers quoted by him cite fire injury and borers and other insects 
as causes for this recession. 

Long (48, p. 8) considers a root rot due to ArmAllaria mellea as 
" very probably an important factor in the gradual recession of the 
chestnut" in North Carolina. It seems probable that all of the 
above-mentioned factors, and perhaps others, have played a part in 
the destruction of the chestnut in this region. 

RELATIVE SUSCEPTIBILITY OF SPECIES OF CASTANEA. 

The importance of Castanea dentata as a timber and nut tree and 
its abundance in eastern North America, where the blight is preva- 
lent, has made the chestnut blight an object of much investigation. 
Descriptions of the nature and importance of the disease, the rate 
of its spread, methods of distribution, and attempted methods of 
control have been given in detail by Anderson (1-5) , Clinton (12-15) , 
Heald (39-41), Metcalf (51 and 52), Metcalf and Collins (53), Kan- 
kin (62), and others. It may be sufficient here to state that the 
fungus enters the host through a wound in the bark, probably never 
or very rarely through lenticels or natural cracks, grows chiefly in 
the cambium, penetrating for only short distances into the wood, 
and kills the tree or branch by girdling. Once a tree is attacked, 
it is only a question of time till it succumbs. 

The chinquapin (Castanea pumila) was found by Murrill (58) in 
1908 to be attacked b}^ Endothia parasitica. Rogers and Gravatt 
(65) in 1915 made inoculations of E. parasitica on C. pumila and 
found that the parasite grew as rapidly on this host as on C. dentata. 
They attribute the apparent resistance of the chinquapin to its com- 
parative freedom from bark injury, a view also held by other writers. 
Pantanelli (60) and Metcalf (52) have proved that the European 
chestnut is readily susceptible to the disease. 

The only chestnuts thus far observed which show any resistance 
to Endothia parasitica are those of oriental origin. Metcalf (51) 
first pointed out the resistance of the Japanese chestnut. This 
observation has since been confirmed hy Clinton (18, p. 375), who 
" failed to produce the disease in a Japanese variety in the [Conn.] 
station 3^ard, although the bark was inoculated in 16 different places." 

Van Fleet (84), in describing the spread of the chestnut blight in 
his breeding plats at Washington, D. C, says (p. 21) : " The Asiatic 
chestnuts and the chinquapin-Asiatic hybrids are plainly highly 
resistant." 



ENDOTHIA PARASITICA AND RELATED SPECIES. 73 

Morris (56) sums up eight years' observation of the effect of the 
chestnut blight on 2G species and varieties of chestnuts at Stamford, 
Conn., as follows: 

Every one of the 5,000 American chestnut trees became blighted * * * 
None of [the grafted varieties or seedlings of European and Asiatic varieties 
appear] to be as vulnerable as the American chestnut, but most of mine are 
now dead. Korean chestnuts and chestnuts from the Aomori regions in 
Japan resisted the blight until six years of age. Since that time they 
have shown a marked tendency to blight, but resist it better than does 
the American chestnut * * * None of the American species of chinquapin 
* * * has blighted with the exception of two limbs * * * None of the 
specimens of Castanca alnifolia [or] * * * of Castanca mollissima has 
blighted, but these latter include only five trees. 

These observations as to the resistance of the oriental varieties of 
chestnut when grown in America are of particular interest in con- 
nection with the observations of Meyer in the region where he dis- 
covered Endothia parasitica native. In his letter to Fairchild, writ- 
ten from Santunying, China, June 1, 1913, Meyer makes the following 
notes with reference to the effect of the blight in that region : 

This blight does not by far do as much damage to Chinese chestnut trees as 
to the American ones * * * 

Not a single tree could be found which had been killed entirely by this 
disease, although there might have been such trees which had been removed 
by the ever-active and economic Chinese farmers * * * 

Dead limbs, however, were often seen and many a saw wound showed whore 
limbs had been removed * * * 

The wounds on the majority of the trees were in the process of healing 
over * * * 

Old wounds are to be observed here and there on ancient trees. 

Meyer's photographs taken near Santunying substantiate his state- 
ments. Certainly no specimens of C. dentata in a blight-infested 
region in this country could survive to the age of the Chinese chest- 
nuts shown in his photographs. 

That the Chinese chestnuts are by no means uniformly resistant, 
however, is clearly shown by Meyer's later notes. On the label of a 
package of Endothia parasitica collected on chestnut at Tachingko, 
Shantung, China, March 21, 1911, he writes, "Trees very severely 
attacked, many dying off," and in a letter written from the same 
place he says, " A serious canker ; many of the trees here were killed 
by it." 

Further evidence that the virulence of Endothia parasitica on Chi- 
nese chestnut differs in different parts of China is found in subse- 
quent communications from Meyer. From a point near Chingtsai, 
Chekiang, China, on July 15, 1915, he writes: "All around Hang- 
chow and west of it one finds the chestnut trees seriously attacked by 
this destructive bark fungus." 

On July 11, 1915, near Changhua, Chekiang, China, he com- 
ments, "With the exception of near Taianfu, Shantung, chestnuts 



74 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

are much more severely attacked in the Chekiang Province than 
either in Chihli, Shansi, or Shensi. Could the greater humidity of 
central China be of assistance to a more vigorous development of 
this destructive fungus?" 

COMPARISON OF HOST RELATIONS. 

It will be seen from the above description of the host relations of 
the various species that while some other members of the genus 
(E. gyrosa, e. g.) may have slight parasitic tendencies, Endothia 
parasitica alone is an active parasite. The contrast is still more 
striking in the section of the genus to which E. parasitica belongs, 
for E. fluens and E. fluens mississippiensis, which resemble E. para- 
sitica so closely in their morphological characters, and to a less 
degree on culture media, and are common on Castanea, are almost 
purely saprophytic. This fact is established by the work of Ander- 
son (2), Clinton (18), and others, and by two years' field observa- 
tions and several thousand inoculations made by the writers and 
their colleagues. 

The host relations of the parasite are equally striking. Although 
Endothia parasitica is so pathogenic on Castanea dentata that this 
tree has been practically exterminated over several hundred square 
miles of its natural range and its extinction is threatened, the fungus 
has been only occasionally found as even a weak parasite on the 
closely related genus Quercus, and never, to the writers' knowledge, 
on Fagus. 

During the course of this work the writers have been continually 
impressed with the possibilities of a physiological study of E. para- 
sitica and one or more closely related species which might throw 
some light on the fundamental question of the nature and cause of 
parasitism. No other case is known to the writers of a virulently 
parasitic fungus and a closely related purely saprophytic one which 
will grow readily and fruit on a large variety of artificial media, 
which are readily distinguishable on those media, and remain con- 
stant for hundreds of generations. 

SUMMARY. 

The pathological and economic importance of this group of fungi 
was first recognized when the chestnut-blight fungus was discov- 
ered in New York in 1904. 

This organism was first referred to the genus Diaporthe, but 
was later shown to belong to the genus Endothia. 

The specific identity, relationships, and native home of this para- 
site were at first uncertain. Some pathologists considered it a native 
organism which was attracting attention and causing injury chiefly 



ENDOTHIA PARASITICA AND RELATED SPECIES. 75 

by reason of the weakened condition of the chestnut trees. Others 
believed it to be of foreign origin. Its recent discovery in China 
and Japan has settled this question. 

To determine positively the identity of the organism, a thorough 
study was made of the types or authentic specimens of all the species 
of Endothia obtainable. As a result of this work a revision of avail- 
able species of the genus is presented. This is based upon the field 
and laboratory study of over 600 collections. Over 4,000 cultures 
have also been studied. 

Endothia gyrosa (Schw.) Fr. is the type of the genus, which is 
naturally divided into two sections, chiefly by the character of the 
ascospores. In section 1 they are short, cylindric to allantoid, and 
continuous or only pseudoseptate. This section contains two species, 
E. gyrosa and E. singularis. 

Section 2 has oblong- fusiform to oblong-ellipsoid uniseptate as- 
cospores. This contains four species and one variety, Endothia 
fluens, E. fiuens mississippiensis, E. longirostris, E. tropicalis, and 
E. parasitica. E. tropicalis is a hitherto unrecognized species. 

Radiating layers of yellowish or buff mycelium situated in the 
bark and cambium of the host are found to be constant and dis- 
tinctive characteristics of Endothia parasitica. None of the other 
species studied shows this character. 

All species of the genus possess a stroma having a distinctive 
yellow to reddish color. 

There is no division of stroma into distinct layers, as described by 
some authors. Pycnidia or perithecia may arise in any portion of 
the stroma. Most commonly where pycnidia and perithecia are both 
present the pycnidia are above the perithecia, though the reverse 
arrangement is sometimes observed and all intermediate conditions 
frequently occur. 

The stromata of the species of section 1 are larger, more erumpent, 
and contain more numerous pycnidia than those of section 2. En- 
dothia singularis is especially striking in this respect. The stromata 
of section 2 are smaller and very similar in all the species. 

The pycnidia consist of more or less irregular chambers or locules 
in the stroma. 

The pycnospores are small in most species and furnish no very 
distinctive specific characters. The pycnospores of Endothia trop- 
icalis are, however, constantly larger and more variable in size than 
those of the other species. 

Paraphyses have been described by some authors, but have never 
been observed by the writers. 

The ascospores in the species of section 1 are very similar in size 
and shape. Those in section 2, though similar, have been found by 
thorough study and careful measurement to show constant though 



76 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

slight differences, as indicated in the tables of measurements and 
ratios. 

Numerous cultures of all the species on a variety of media show 
that each species has constant and distinctive characters of growth 
and color. 

All the species grew equally well in light or darkness, and no de- 
cided differences in temperature relations have been demonstrated. 

The species appear to have well-defined geographic limits of 
distribution, which have been approximately determined for the 
American species. The distribution of the species does not coincide 
with that of the hosts, but seems to be determined in part by soil 
and climatic conditions. 

Endothia fiuens has the widest distribution, being frequent and 
widely distributed in Europe and the eastern United States, and also 
occurring in Asia. 

Endothia parasitica is evidently of oriental origin. Specimens 
have been received from five rather widely separated localities in 
China and from two localities in Japan. In the eastern United 
States it is now abundant from Maine to North Carolina and is 
rapidly spreading south and west. It has already destroyed most 
of the chestnut trees within a radius of 100 miles of New York City. 

The species have rather definite host relations. 

Endothia gyrosa has been found on five genera of plants, viz, Cas- 
tanea, Fagus, Liquidambar, Quercus, and Vitis. 

Endothia singularis occurs, so far as known, only on Quercus 
species. 

Endothia fiuens has been found in America only on Castanea and 
Quercus, but in Europe it occurs on Alnus, Carpinus, Castanea, 
Corylus, Quercus, and Ulmus, and has been reported on Aesculus, 
Fagus, and Juglans. 

Endothia fiuens mississippiensis has been found only on Castanea 
and Quercus. 

Endothia tropicalis is known only on Elaeocarpus. 

Endothia parasitica has been found on Acer, Carya, Castanea, 
Quercus, and Ehus, but at present is only known as a serious para- 
site on Castanea. 

Upon the American species of Castanea it is actively parasitic 
under all the conditions of soil and climate observed. Oriental 
species of chestnut are more or less resistant to the disease both in 
America and their native homes. 

None of the species except Endothia parasitica has thus far been 
found to be actively parasitic. 



LITERATURE CITED. 

(1) Anderson, P. J. 

1914. Morphology and life history of the chestnut blight fungus. Com. 
Invest, and Control Chestnut Tree Blight Disease in Penn. Bui. 
7, 44 p., 17 pi. 1913. 

(2) and Anderson, H. W. 

1912. The chestnut blight fungus and a related saprophyte. In Phyto- 

pathology, v. 2, no. 5, p. 204-210. 

(3) 1912. Endothia virginiana. In Phytopathology, v. 2, no. 6, p. 261-262. 

(4) 1913. The chestnut blight fungus and a related saprophyte. Penn. 

Chestnut Tree Blight Com. Bui. 4, 26 p., 6 fig. 

(5) and Babcock, D. C. 

1913. Field studies on the .dissemination and growth of the chestnut 

blight fungus. Penn. Chestnut Tree Blight Com. Bui. 3, 45 p., 
14 pi. 

(6) and Rankin, W. H. 

1914. Endothia canker of chestnut. N. Y. Cornell Agr. Exp. Sta. Bui. 

347, p. 531-618, fig. 77-101, pi. 36-40 (1 col.). Bibliography, p. 
611-618. 

(7) Balls, W. L. 

1908. Temperature and growth. In Ann. Bot., v. 22, no. 88, p. 557-591, 
11 fig. 

(8) Berkeley, M. J. 

1836. British Fungi ... 386 p. London. (Smith, J. E. English 
Flora, v. 5, pt. 2.) 

(9) and Broome, C. E. 

1875. Enumeration of the fungi of Ceylon. In Jour. Linn. Soc. [London] 
Bot., v. 14, p. 29-140, pi. 2-10. 

(10) 1877. Supplement to the enumeration of fungi of Ceylon. In Jour. Linn. 

Soc. [London] Bot., v. 15, p. 82-86, pi. 2. 

(11) Cesati, Vincenzo, and Notaris, G. de. 

1S63. Schema di classificazione degli sferiacei Italici aschigeri ... In 
Comm. Soc. Crittog. ItaL, v. 1, p. 207, 240. 

(12) Clinton, G. P. 

Chestnut bark disease [1907]. In Conn. Agr. Exp. Sta. 31st/32d Ann. 
Rpt. [1906] /OS, p. 345-346. 

(13) 1908. Chestnut bark disease, Diaporthe parasitica Murr. [1908]. In 

Conn. Agr. Exp. Sta. 31st/32d Ann Rpt. [1906] /08, p. S79-S90. 

(14) 1911. Chestnut bark disease. In Conn. Agr. Exp. Sta. Bien. Rpt. 1909/10, 

p. 716-717, 725. 

(15) 1912. Some facts and theories concerning chestnut blight. In Penn. 

Chestnut Blight Conf. Rpt. 1912, p. 75-83, 9 pi. 

(16) 1912. Chestnut blight fungus and its allies. In Phytopathology, v. 2, 

no. 6, p. 265-269. 

(17) 1912. The relationships of the chestnut blight fungus. In Science, n. s., 

v. 36, no. 939, p. 907-914. 

77 



78 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

(18) 1913. Chestnut hark disease, Ehdothia gyrosa var. parasitica (Murr.) 

Clint. In Conn. Agr. Exp. Sta. Ann. Rpt. 1911/12, p. 359-453, 
pi. 21-28. 

(19) Cook, M. T., and Taubenhaus, J. J. 

1911. Relation of parasitic fungi to the contents of the cells of the host 

plants. I. The toxicity of tannin. Del. Agr. Exp. Sta. Bui. 91, 
77 p., 43 fig. 

(20) Cooke, M. C. 

1878. The fungi of Texas. In Ann. N. Y. Acad. Sci., v. 1, no. 5/6, p. 
177-187. 

(21) Cukrey. Frederick. 

1858. Synopsis of the fructification of the compound Sphaeriae of the 
Hookerian herbarium. In Trans. Linn. Soc. London, v. 22, pt. 3, 
p. 257-287, pi. 45-49. 

(22) 1865. Supplementary observations on the Sphaeriae of the Hookerian 

herbarium. In Trans. Linn. Soc. London, v. 25, pt. 2, p. 239-262. 

(23) Curtis, M. A. 

1867. ... A catalogue of the Indigenous and Naturalized Plants of the 
State. 158 p. Raleigh, N. C. (Geological and Natural History 
Survey of North Carolina, pt. 3. Botany.) 

(24) Detwilek, S. B. 

1914. Observations on sanitation cutting in controlling the chestnut blight 
in Pennsylvania. Final Rpt. Penn. Chestnut Tree Blight Com. 
1913, p. 63-73, 1 pi., 3 maps. 

(25) Earle, F. S. 

1901. Some fungi from Porto Rico. In Muhlenbergia, v. 1, no. 2, p. 10-23. 

(26) Ellis, J. B.. and Everhart, B. M. 

1892. The North American Pyrenomycetes. . . . 793 p., 41 pi. Newfield, 
N. J. 

(27) Fairchild, D. G. 

1913. The discovery of the chestnut bark disease in China. In Science 

n. s., v. 38, no. 974, p. 297-299. 

(2S) Farlow, W. G. 

1912. The fungus of the chestnut-tree blight. In Science, n. s., v. 35, no. 

906, p. 717-722. 

(29) Faull, J. H., and Graham, G. H. 

1914. Bark disease of the chestnut in British Columbia. Forestry Quart., 

v. 12, no. 2, p. 201-203. 

(30) Fries, E. M. 

1882. Systema Mycologicum. ... v. 2. Lundae. 

(31) 1828. Elenchus Fungorum. ... v. 2. Gryphiswaldiae. 

(32) 1830. Eclogae fungorum. . . . In Linnaea, Bd. 5, Heft. 4, p. 497-553. 

(33) 1849. Summa Vegetabilium Scandinaviae. . . . sect. 2. Upsaliae. 

(34) Fuckel, Leopold. 

1861. Enumeratio Fungorum Nassoviae. 126 p., 1 col. pi. Wiesbaden. 

(35) 1869-70. Symbolae Mycologicae. Beitrage zur Kenntniss der Rheinis- 

chen Pilze. 459 p., 6 col. pi. Wiesbaden. (Jahrb. Nassau. Ver. 
Naturk., Jahrg. 23/24.) 



ENDOTHIA PAEASITICA AND BELATED SPECIES. 79 

(36) FUISTING, WlLHELM. 

1867. Zur Entwickelungsgeschichte der Pyrenomyceten. In Bot. Ztg., 
Jahrg. 25, No. 23, p. 177-181; No. 24, p. 185-189; No. 25, p. 
193-198; No. 39, p. 305-311. 

(37) Fulton, H. R. 

1912. Recent notes on the chestnut bark disease. In Penn. Chestnut 

Blight Conf. Rpt. 1912, p. 48-56. 

(38) Gulliver, F. P. 

1914. [Report of] geographic work. In Final Rpt. Penn. Chestnut Tree 

Blight Com. 1913, p. 52-53. 

(39) Heald, F. De F. 

1913. The symptoms of chestnut tree blight and a brief description of 

the blight fungus. Penn. Chestnut Tree Blight Com. Bui. 5, 
15 p., 16 pi. 

(40) Gardner, M. W., and Studhalter, R. A. 

1915. Air and wind dissemination of ascospores of the chestnut blight 

fungus. In Phytopathology, v. 3, no. 6, p. 493-526. 

(41) and Studhalter, R. A. 

1913. Preliminary note on birds as carriers of the chestnut blight fungus. 

In Science, n. s., v. 38, no. 973, p. 278-280. 

(42) Hitchcock, Edward. 

1829. A Catalogue of Plants Growing without Cultivation in the Vicinity 
of Amherst College. 64 p. Amherst, Mass. 

(43) Hohnel, Franz von 

1909. Fragmente zur Mykologie. IX. Mitteilung, Nr. 407 bis 467. In 
Sitzber. K. Akad. Wiss. [Vienna], Math. Naturw. Kl., Abt. 1, 
Bd. US, Heft 9, p. 1461-1552, 1 illus. 

(44) 1913. Fragmente zur Mykologie. XV. Mitteilung, Nr. 793 bis 812. In 

Sitzber. K. Akad. Wiss. [Vienna], Math. Naturw. Kl., Abt. 1, 
Bd. 122, Heft 2, p. 255-309, 7 fig. 

(45) Keefer, W. E. 

1914. Pathological histology of the Endothia canker of chestnut. In 

Phytopathology, v. 4, no. 3, p. 191-200, 3 fig. 

(46) Koppen, W. P. 

1901. Versuch einer Klassification der Klimate vorzugsweise nach ihren 
Beziehungen zur Pflanzenwelt. 45 p., 2 illus., tab., 2 fold. maps. 
Leipzig. 

(47) Livingston, B. E., and Livingston, Grace J. 

1913. Temperature coefficients in plant geography and climatology. In 

Bot. Gaz., v. 56, no. 5, p. 349-375, 3 fig. 

(48) Long, W. H. 

1914. The death of chestnuts and oaks due to Armillaria mellea. U. S. 

Dept. Agr. Bui. 89, 9 p., 2 pi. 

(49) Merkel, H. W. 

1906. A deadly fungus on the American chestnut. In 10th Ann. Rpt. 
N. Y. Zool. Soc. 1905, p. 97-103, illus. 



80 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

(50) Mekriam, C. H. 

1895. Laws of temperature control of the geographic distribution of terres- 
trial animals and plants. In Nat. Geog. Mag., v. 6, p. 229-238, 
pi. 12-14 (col. maps). 

(51) Metcalf, Haven. 

1908. The immunity of the Japanese chestnut to the bark disease. In 
U. S. Dept. Agr., Bur. Plant Indus. Bui. 121, p. 55-56. 

(52) 1912. Diseases of the chestnut and other trees. In Trans. Mass. Hort. 

Soc. 1912, pt. 1, p. 69-95. 

(53) and Collins, J. F. 

1910. The chestnut bark disease. In Science, n. s., v. 31, no. 802, p. 748. 

(54) Montagne, J. F. C. 

1834. Notice sur les plantes cryptogaines, recemment decouvertes en 
France, contenant aussi l'indication precise des localitgs de 
quelques esp£ces les plus rares de la flore francaise. In Ann. Sci. 
Nat. Bot, s. 2, t. 1, p. 295-307, 337-349, pi. 11-13 (2 col.). 

(55) 1855. Cryptogamia Guyanensis . . . In Ann. Sci. Nat. Bot. s. 4, t. 3, p. 

91-144, pi. 5. 

(56) Morris, R. T. 

1914. Chestnut blight resistance. In Jour. Heredity, v. 5, no. 1, p. 26-29, 

fig. 14-15. 

(57) Mureill, W. A. 

1906. A new chestnut disease. In Torreya, v. 6, no. 9, p. 186-189, fig. 2. 

(58) 190S. The chestnut canker. In Torreya, v. 8, no. 5, p. 111-112. 

(59) Nowell, William. 

1915. Diseases of lime trees in forest districts. Imp. Dept. Agr. West 

Indies, Pamphlet Series 79, 41 p., 2 fig., 5 pi. 

(60) Pantanelli, Enrico. 

1912. Su la supporta origine europea del cancro americano del castagno. 

In Atti R. Accad. Lincei, Rend. CI. Sci. Fis., Mat. e Nat., s. 5, 
v. 21, sem. 2, fasc. 12, p. 869-875. 

(61) Petri, Ltjigi. 

1913. Sopro una nuova specie di Endothia, E. pseudoradicalis. In Atti 

R. Accad. Lincei, Rend. CI. Sci. Fis., Mat. e Nat., s. 5, v. 22, 
sem. 1, fasc. 9, p. 653-658, 2 fig. 

(62) Rankin, W. H. 

1914. Field studies on the Endothia canker of chestnut in New York 

State. In Phytopathology, v. 4, no. 4, p. 233-260, 2 fig. pi. 11. 

(63) Rehm, Heinrich. 

1907. Ascomycetes exs. fasc. 39. In Ann. Mycol, v. 5, no. 3, p. 207-213. 

(64) Ridgway, Robert. 

1912. Color Standards and Color Nomenclature. 43 p., 53 pi. Washing- 
ton. 

(65) Rogers, J. T., and Gravatt, G. F. 

1915. Notes on the chestnut bark disease. In Phytopathology, v. 5, no. 1, 

p. 45-47. 



ENDOTHIA PARASITICA AND RELATED SPECIES. 81 

(66) Rudolphi, Fr. 

1829. Plantarum vel novarum vel minus cognitarum descriptiones. Decas 
secunda. In Linnaea, Bd. 4, Heft 3, p. 387-395. 

(67) Ruhland, Willy. 

1900. Untersuchungen zu einer Morphologie der stromabildenden Sphae- 
riales auf entwickelungsgeschichtlicher Grundlage. In Hed- 
wigia, Bd. 39, Heft 1, p. 1-79, pi. 1-3. 

(68) Saccakdo, P. A. 

1873. Mycologiae venetae specimen. In Atti Soc. Veneto-Trentina Sci. 
Nat. Padova, v. 2, fasc. 1, p. 53-96, pi. 4-5 (col.) ; fasc. 2, p. 
97-264, pi. 6-17 (col.). 

(69) 1882-1905. Sylloge Fungorum, v. 1, 8, 17. Patavii, 1882, 1889, 1905. 

(70) 1883. Genera Pyrenomycetum Schematica Delineata. 8 p., 14 pi. Patavii. 

(71) 1906. Notae mycologicae. Series VII. In Ann. My col., v. 4, no. 3, p. 

273-278. 

(72) Schweinitz, L. D. VON. 

[1822]. Synopsis Fungorum Carolinae Superioris . . . 105 p., 2 col. pi. 
n. p. 

(73) 1825. Description of a number of new American species of Sphaeriae. In 

Jour. Acad. Nat. Sci. [Phila.], v . 5, pt. 1, p. 3-16, 2 pi. 

(74) 1S32. Synopsis fungorum in America boreali media degentium ... In 

Trans. Amer. Phil. Soc, n. s., v. 4, p. 141-316, pi. 19. 

(75) Shear, C. L. 

1912. The chestnut-blight fungus. In Phytopathology, v. 2, no. 5, p. 211- 

212. 

(76) and Stevens, Neil E. 

1913. The chestnut-blight parasite (Endothia parasitica) from China. 

In Science, n. s., v. 38, no. 974, p. 295-297. 

(77) 1913. Cultural characters of the chestnut-blight fungus and its near rela- 

tives. In U. S. Dept. Agr., Bur. Plant Indus. Cir. 131, p. 3-18. 

(78) 1916. The discovery of the chestnut-blight parasite (Endothia parasitica) 

and other chestnut fungi in Japan. In Science, n. s., v. 43, no. 
1101, p. 173-176. 

(79) Sowerby, James. 

1814. Colored Figures of English Fungi or Mushrooms. Sup. London. 
PI. 438 is pt. of pi. 420. 

(80) Sprengel, Kurt. 

1827. Systema Vegetabilium. v. 4, pars 1. Gottingae. 

(81) Sydow. Hans, and Sydow, Paul. 

1912. Novae fungorum species — VII. In Ann. Mycol., v. 10, no. 1, p. 

77-85. 

(82) Traverso, G. B. 

1906. Pyrenomycetae . . . In Societa Botanica Italiana, Flora Italica 
Cryptogama. pars 1, Fungi, v. 2, fasc. 1, p. 180-182. 

(83) Tulasne, L. R., and Tulasne, Charles. 

1863. Selecta Fungorum Carpologia ... t. 2. Parisiis. 
43737°— Bull. 3S0— 17 6 



82 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 

(84) Van Fleet, Walter. 

1914. Chestnut breeding experience. In Jour. Heredity, v. 5, no. 1, p. 19- 
25, fig. 9-13. 

(85) Winter, Georg. 

1887. Die Pilze . . . 928 p. Leipzig. (Rabenhorst, Ludwig. Krypto- 
gamen-Flora . . . Aufl. 2, Bd. 1, Abt. 2.) 

(86) Zon, Raphael 

1914. Meteorological observations in connection with botanical geography, 
agriculture, and forestry. In Mo. Weather Rev., v. 42, no. 4, p. 
217-223, 1 fig. 



ADDITIONAL copies 

OF THIS PUBLICATION MAY BE PROCURED FROM 

THE SUPERINTENDENT OF DOCUMENTS 

GOVERNMENT PRINTING OFFICE 

WASHINGTON, D. C. 

AT 

35 CENTS PER COPY 



: 



Gaylord Bros. 



Makers 



Syracuse, 



N. Y. 



PAT. JAN. 21,1908 



